Portable oxygen delivery device

ABSTRACT

Devices, systems, and methods, include an oxygen delivery device that includes an oxygen delivery module, at least one sensor to detect patient breathing, and a controller configured to control the oxygen delivery module to cause the oxygen delivery module to deliver oxygen to the patient based on data from the at least one sensor such that in response to a determination, based on data from the at least one sensor, that no breathing is detected for a first pre-determined period of time, the controller causes the oxygen delivery module to deliver oxygen to the patient in continuous flow mode, and in response to a determination, based on additional data from the at least one sensor, that breathing is detected for a second period of time, the controller causes the oxygen delivery module to deliver oxygen to the patient in a pulse flow mode.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims benefit and priority to U.S. ProvisionalPatent Application No. 61/321,824, filed Apr. 7, 2010, and entitled“Portable Oxygen Concentration System and Method of Using the Same,” thecontent of which is hereby incorporated by reference in its entirety.

FIELD

This disclosure relates generally to a device, mechanism and method foran oxygen delivery device, and in particular, to a portable oxygenconcentration system for an ambulatory respiratory subject that allowsthe subject to lead a more normal and productive life.

BACKGROUND

Supplemental oxygen is necessary for patients suffering from lungdisorders; for example, pulmonary fibrosis, sarcoidosis, or occupationallung disease. For such patients, oxygen therapy is an increasinglybeneficial, life-giving development. While not a cure for lung disease,supplemental oxygen increases blood oxygenation, which reverseshypoxemia. This therapy prevents long-term effects of oxygen deficiencyon organ systems—in particular, the heart, brain and kidneys.

Oxygen treatment is also prescribed for Chronic Obstructive PulmonaryDisease (COPD), which afflicts about twenty-four million people in theU.S., and for other ailments that weaken the respiratory system, such asheart disease and AIDS. Supplemental oxygen therapy is also prescribedfor asthma and emphysema.

The normal prescription for COPD patients requires supplemental oxygenflow via nasal cannula or mask twenty four hours per day. The averagepatient prescription is two liters per minute of high concentrationoxygen to increase the oxygen level of the total air inspired by thepatient from the normal 21% to about 40%. While the average oxygen flowrequirement is two liters per minute, the average oxygen concentratorhas a capacity of four to six liters of oxygen per minute. This extracapacity is occasionally necessary for certain patients who havedeveloped more severe problems, are not generally able to leave the home(as ambulatory patients) and do not require a portable oxygen supply.

There are currently three modalities for supplemental medical oxygen:high pressure gas cylinders, cryogenic liquid in vacuum insulatedcontainers or thermos bottles commonly called “dewars,” and oxygenconcentrators. Some patients require in-home oxygen only while othersrequire in-home as well as ambulatory oxygen depending on theirprescription. All three modalities are used for in-home use, althoughoxygen concentrators are preferred because they do not require dewarrefilling or exchange of empty cylinders with full ones. Some of theconventional home oxygen concentrators, however, do have theirdrawbacks. They consume relatively large amounts of electricity (250-500Watts), are relatively large (about the size of a night stand), arerelatively heavy (weight about 30-50 lbs.), emit quite a bit of heat,and are relatively noisy.

Only small high pressure gas bottles and small liquid dewars are trulyportable enough to be used for ambulatory needs (outside the home).Either modality may be used for both in-home and ambulatory use or maybe combined with an oxygen concentrator which would provide in-home use.

As described below, the current oxygen-supplying methods and deviceshave proven cumbersome and unwieldy and there has been a long-felt needfor an improved portable device for supplying oxygen to the user.

For people who need to have oxygen and operate away from anoxygen-generating or oxygen-storage source such as a stationary oxygensystem (or even a portable system which cannot be readily transported),the two most prescribed options generally available to patients are: (a)to carry with them small cylinders typically in a wheeled stroller; and(b) to carry portable containers typically on a shoulder sling. Bothgaseous oxygen and liquid oxygen options have substantial drawbacks, butfrom a medical view, both have the ability to increase the productivelife of a patient.

A drawback of the gaseous oxygen option is that the small cylinders ofgaseous oxygen can only provide gas for a short duration. Anotherdrawback is that a patient's high-pressure gaseous oxygen cylinders arenot allowed in some locations such as airplanes because of safetyconsiderations. A further drawback of the gaseous oxygen option is therefill requirement for oxygen once the oxygen has been depleted from thecylinder. These small gas cylinders must be picked up and refilled bythe home care provider at a specialized facility. This requires regularvisits to a patient's home by a provider and a substantial investment insmall cylinders by the provider because so many are left at thepatient's home and refilling facility. Although it is technicallypossible to refill these cylinders in the patient's home using acommercial oxygen concentrator that extracts oxygen from the air, thistask would typically require an on-site oxygen compressor to boost theoutput pressure of the concentrator to a high level in order to fill thecylinders. Some disadvantages of common on-site oxygen compressors arethat they are expensive, loud and emit a lot of heat.

Additionally, attempting to compress the oxygen in pressurized canistersin the home is potentially dangerous, especially for untrained people.

This approach presents several safety concerns for in-home use. Forexample, in order to put enough of this gas in a portable container, itmust typically be compressed to high pressure (2000 psi). Compressingoxygen from 5 psi (the typical output of an oxygen concentrator) to 2000psi will produce a large amount of heat (enough to raise the temperature165 degrees C. per stage based on three adiabatic compression stageswith intercooling.) This heat, combined with the oxygen which becomesmore reactive at higher pressures, sets up a potential combustion hazardin the compressor in the patient's home. Thus, operation of ahigh-pressure gas system in the patient's home is dangerous and not apractical solution.

The convenience and safety issues are not the only drawbacks of thiscompressed oxygen approach. Another drawback is that the compressors orpressure boosters needed are costly because they require special careand materials needed for high pressure oxygen compatibility.

Turning now to the liquid oxygen storage option, its main drawback isthat it requires a base reservoir—a stationary reservoir base unitwithin the patient's home about the size of a standard beer keg—whichmay be refilled about once a week from an outside source. Liquid oxygencan then be transferred from the patient's base unit to a portabledewar, which can be used by the ambulatory patient. Also, with theliquid oxygen option, there is substantial waste, as a certain amount ofoxygen is lost during the transfer to the portable containers and fromevaporation. It is estimated that 20% of the entire contents of the basecylinder will be lost in the course of two weeks because of losses intransfer and due to normal evaporation. These units will typically boildry over a period of 30 to 60 days even if no oxygen is withdrawn.

Home refilling systems that produce liquid oxygen and have thecapability of refilling portable liquid oxygen dewars have beenproposed. However, these devices require the user to perform the task ofrefilling bottles and add tens of dollars per month to the user'selectric bill, which may not be reimbursable.

There are other complications with these portable high-pressurecylinders and liquid dewars. Typically, supplemental oxygen is suppliedto the patient by a home care provider, in exchange for which theprovider receives a fixed monetary payment from insurance companies orMedicare regardless of the modality. Oxygen concentrators are preferredby the provider as the least expensive option for supplying thepatient's at-home needs. For outside the home use, however, only smallhigh-pressure gas bottles and small liquid dewars are portable enough tobe used for ambulatory needs. Either one of these two modalities may beused for both in-home and ambulatory use or may be combined with anoxygen concentrator, which would provide in-home use. In either case,the home care provider must make costly weekly or biweekly trips to thepatient's home to replenish the oxygen. One of the objectives of thesystems, devices, and methods disclosed herein is to eliminate thesecostly “milk runs.”

So-called “portable” oxygen concentrators are commercially available forproviding patients with gaseous oxygen by converting ambient air intoconcentrated gaseous oxygen. However, such devices are still relativelybulky (e.g., they are packaged in a suitcase) and are portable only inthe sense that they are capable of being transported to another point ofuse via an automobile or an airplane. An example of such a transportabledevice is a 3 LPM concentrator mounted on its own cart. This exampledevice weighs 18 lbs., with the battery, and also requires about 145Watts of power. A further example device is one that weighs about 21lbs. with battery and has a similar flow rate and power requirements tothe above devices.

Even without a battery, these devices are too heavy for the averageambulatory respiratory patient. With the weight of a battery, theseconventional devices are not “portable” in the true sense of the wordbecause transportation from one point to another is still cumbersome.Because these devices have relatively large power consumptionrequirements, they also require a sizable battery.

Further, in addition to the weight and power consumption problems withthe above oxygen concentrators, none of these conventional concentratorsare particularly quiet. They produce noise levels similar to thoseproduced by a home concentrator. For example, some of these devices canproduce noise at 55 dBA (decibels), which is about the sound level of anormal conversation. Consequently, none of these conventional oxygenconcentrators are suitable for use in environments where low noise isespecially important, e.g., restaurants, libraries, churches andtheatres.

SUMMARY

Thus, a long-felt need exists for a truly portable oxygen concentrationsystem that eliminates the need for high-pressure gas cylinders andliquid dewars, the constant refilling/replacing requirements associatedwith high-pressure gas cylinders and liquid dewars, and the need for aseparate home oxygen concentration system for ambulatory respiratorypatients. The portable oxygen concentration systems and devicesdescribed herein are light enough so that, even with a battery, anaverage ambulatory respiratory patient can carry the device. Inherently,the oxygen concentrator devices described herein are implemented to haverelatively low power consumption requirements so that a light-weightbattery pack or other energy source could be used. Further, the devicesdescribed herein are small enough so that they can be convenientlycarried by a user, emit a relatively low amount of noise and emit arelatively small amount of heat.

An aspect of the present disclosure involves a portable oxygenconcentrator system, also referred to herein as an oxygen deliverydevice, adapted to be readily transported by a user. The portable oxygenconcentrator system includes a rechargeable energy source and aconcentrator (also referred to herein as an oxygen delivery module)powered by the energy source. The concentrator converts ambient air intoconcentrated oxygen gas for the user and includes a plurality ofadsorption beds and a rotary valve assembly. The rotary valve assemblyis relatively rotatable is with respect to the plurality of adsorptionbeds to provide valving action for selectively transferring fluidsthrough the plurality of adsorption beds to convert ambient air intoconcentrated oxygen gas for the user. In some embodiment, the ratio ofadiabatic power to oxygen flow for the concentrator is in the range of6.2 W/LPM to 23.0 W/LPM.

Another aspect of the present disclosure involves a rotary valveassembly for a pressure swing adsorption system having a plurality ofadsorption beds. The rotary valve assembly includes a valve port plateand a rotary valve shoe with respective engaged surfaces and arerotatable about a common center of rotation to provide valving actionfor selectively transferring fluids therethrough. The valve port plateincludes at least two ports interconnected with at least two adsorptionbeds. The rotary valve shoe includes a second valve surface opposite theengaged surface with at least one equalization passage to register withthe at least two ports of the port plate to equalize pressure betweenthe at least two adsorption beds.

In one aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module to produce at leastconcentrated oxygen at a controllable purity level from air, a gasmoving device to deliver the air to the oxygen delivery module, at leastone controllable motor to controllably drive the gas moving device, anenergy source to power at least the at least one controllable motor, apressure sensor to determine a pressure level produced in the oxygendelivery device, and a purity sensor to determine oxygen purity valueproduced by the oxygen delivery module. The device also includes acontroller to control, based on the determined oxygen purity value andthe pressure level, at least the gas moving device's operations and theoxygen delivery module's operations so as to cause the pressureresulting from the operation of the gas moving device to besubstantially at a pre-determined pressure value and to cause the puritylevel of the oxygen produced by the oxygen delivery module to besubstantially at a pre-determined purity value.

Embodiments of the device may include any of the features described inthe present disclosure, as well as any one or more of the followingfeatures.

The oxygen delivery module may include one or more of, for example, apressure swing adsorption system, a vacuum-pressure swing adsorptionsystem, a liquid oxygen storage system, and/or a high pressure gaseousoxygen system.

The pre-determined pressure value may correspond to a minimum acceptablepressure level, and the pre-determined purity value may correspond to aminimum acceptable oxygen purity level such that energy consumption ofthe system is reduced. The minimum acceptable pressure level may bebetween approximately 3-7 psig pressure, and the minimum acceptableoxygen may be between approximately 82-93% oxygen.

The controller may be configured to cause the pressure resulting fromthe operation of the gas moving device to be substantially at thepre-determined pressure value and to cause the purity level of theoxygen produced by the oxygen delivery module to be substantially at thepre-determined purity value in response to a determination that anenergy source to power the oxygen delivery device is a battery. Thebattery may be a rechargeable battery. The oxygen delivery module mayinclude a plurality of adsorption beds, and a valve assembly configuredto direct gas to the plurality of adsorption beds to provide valvingaction for selectively transferring fluids through the plurality ofadsorption beds to separate concentrated oxygen gas from ambient air.

The gas delivery device may be configured to convert a flow of gas froma first pressure to a second pressure. The gas delivery device mayinclude one or more of, for example, a compressor, and/or a vacuum pump.

The oxygen delivery device may further include a rechargeable backupbattery to deliver power to a user interface of the oxygen deliverydevice to indicate change of power supply level (e.g., when power from aprimary power source used to power the oxygen delivery device ischanged, such as when there is a power loss). The rechargeable backupbattery may be configured to power the user interface to indicate powerloss when the primary power source used to power the oxygen deliverydevice cannot deliver power to the oxygen delivery device. The userinterface may include a power loss alarm, and the rechargeable backupbattery may be configured to deliver power to activate the power lossalarm in response to determination that the primary power source cannotdeliver power.

The oxygen delivery device may further include a user interfaceincluding an indicator to indicate that maintenance of the oxygendelivery device is required in response to a determination of deviationsfrom a maintenance schedule required for the oxygen delivery device.

The oxygen delivery device may further include a user interfaceincluding an indicator to indicate time remaining for a battery-basedpower, source included with the oxygen delivery device.

The oxygen delivery device may further include a cart to transport theoxygen delivery device and to elevate the oxygen delivery device toprovide enhanced access by the patient to the oxygen delivery device.

The oxygen delivery device may further include a device interface moduleconfigured to interface with one or more additional devices to enableinteroperability functionality of the oxygen delivery device with theone or more additional devices, the interoperability functionalityincludes one or more of, for example, directing power from a powersource of the oxygen delivery device to the one or more additionaldevices, and/or communicating data between the oxygen delivery deviceand the one or more additional devices. The device interface module mayinclude at least one dedicated port to interface with at least one ofthe one or more additional devices. The one or more additional devicesmay include one or more of, for example, pulse oximeter, pedometer,mathemoglobin monitor, carboxyhemoglobin monitor, totalhemoglobinsensor, a wireless telephone, a wireless modem, and/or a respirationmonitor.

The oxygen delivery device may further include a sound system togenerate acoustic signals to cancel out at least some of the noiseproduced from operation of the oxygen delivery device. The sound systemmay be configured to generate acoustic signals with a phase that isshifted or inverted relative to at least some of the noise produced byoperation of the oxygen delivery device. The sound system may include amicrophone to measure the noise produced from operation of the oxygendelivery device, a controller to determine characteristics of the noisemeasured by the microphone and to control the acoustic signals to begenerated by a speaker, and the speaker to generate the acoustic signalsbased on control data provided by the controller.

The oxygen delivery device may further include one or more of, forexample, a clock, a radio, an ashtray, and/or a cup holder.

The oxygen delivery device may further include a controller to controlat least some operations of the oxygen delivery device, includingcontrolling operations affecting the oxygen delivery module. Thecontroller may include at least one processor based device, and at leastone non-transitory memory storage device to store computer instructions,the computer instructions including instructions that when executed onthe at least one processor-based device cause the at least oneprocessor-based device to receive data indicative that defaultoperational settings of the oxygen delivery device are to be activated,and in response to the received data, activate the default operationalsettings of the oxygen delivery device.

The oxygen delivery device may further include a check valve and gasfilter included within a housing of the oxygen delivery device andpositioned downstream of the oxygen delivery module, the check valve andgas filter configured to prevent moisture present in components of theoxygen delivery device located downstream of the oxygen delivery modulefrom entering the oxygen delivery module.

The oxygen delivery device may further include a purity sensor todetermine oxygen purity value, a coupler coupled to the purity sensor,the coupler including an inlet port to receive gas from an externalsource, and a controller configured to receive data from the puritysensor measuring the purity of oxygen delivered from an external oxygensource, the oxygen from the external oxygen source having a known oxygenpurity level, and calibrate the purity sensor based on the purity valuemeasured by the purity sensor for the oxygen having the known oxygenpurity level delivered from the external oxygen source. The coupler mayinclude a tee fitting.

The oxygen delivery device may further include an internal battery topower, at least partly, the oxygen delivery device, the internal batterylocated within a housing of the oxygen delivery device. The oxygendelivery device may also include an external battery pack secured to thehousing of the oxygen delivery device to supplement power requirementsof the oxygen delivery device.

The oxygen delivery device may further include an internal DC/DC powerconverter placed within a housing of the oxygen delivery device.

The oxygen delivery device may further include a cart to hold the oxygendelivery device, an AC adapter external to a housing of the oxygendelivery device, the AC adapter being mounted on the cart, and a batterypack external to the housing of the oxygen delivery device, the batterypack being mounted on the cart.

The oxygen delivery device may further include an oxygen containercontaining oxygen, the container configured to deliver oxygen whenoxygen produced by the oxygen delivery device is not sufficient to meeta patient's oxygen needs.

The oxygen delivery device may further include an internal AC adapterplaced within a housing of the oxygen delivery device.

The oxygen delivery device may further include one or more of, forexample, an internal battery to power, at least partly, the oxygendelivery device, the internal battery located within a housing of theoxygen delivery device, and an external battery pack secured to thehousing of the oxygen delivery device to supplement power requirementsof the oxygen delivery device. Each of the internal battery and theexternal battery pack may include batteries having maximum dimensionsallowed by regulating agencies.

The oxygen delivery device may further include a device interface moduleincluding one or more universal serial bus (USB) ports to enable theoxygen delivery device to function as one of a slave and a host whenconnected to at least one external device. The one or more USB ports ofthe device interface module may enable the oxygen delivery device toperform one or more of, for example, communicating data to and from theat least one connected external device, upgrading software-basedimplemented functionality of at least one operation of the oxygendelivery device, and/or connecting to one or more additional sensorsconfigured to measure one or more of: environmental conditions,operating conditions of the oxygen delivery device, and/or a patient'stherapeutic conditions.

The oxygen delivery device may further including a cart to transport theoxygen delivery device, the cart including a retractable/foldablehandle. The cart may further include a base to receive a housing of theoxygen delivery device, the housing including integrated wheels suchthat when the housing with the integrated wheels is received on the baseof the cart, the wheels of the housing are used to enable mobility ofthe cart.

The oxygen delivery device may further include a universal power adapterconfigured to connect to a plurality of power outlet types and to adaptpower delivered from the plurality of power outlet types to produce anoutput power with power characteristics required for operation of theoxygen delivery device. The universal power adapter may disposed withina housing of the oxygen delivery device.

The oxygen delivery device may further include a fan to cool the oxygendelivery device, at least one temperature sensor, and a controller tocontrol operation of the fan based on data representative of temperaturemeasured by the at least one temperature sensor. The controller isconfigured to cause one of terminating the operation of the fan andreducing speed of the fan upon a determination, based on the datarepresentative of the temperature, that the measured temperature isbelow a pre-determined temperature threshold.

In another aspect, a method is disclosed. The method includes receivingfrom a purity sensor data representative of oxygen purity value in anoxygen delivery module, receiving from a pressure sensor a pressurelevel value produced by a gas moving device configured to draw air intothe oxygen delivery module, and controlling one or more of, for example,the gas moving device's operations and the oxygen delivery module'soperations based on the received oxygen purity value and the receivedpressure level value to cause the pressure resulting from the operationof the gas moving device to be substantially at a pre-determinedpressure value and to cause the purity level of the oxygen produced bythe oxygen delivery module to be substantially at a pre-determinedpurity value.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the device, as well as any of the following features.

Controlling the at least the gas moving device's operations and theoxygen delivery module's operations may include controlling a motorconfigured to drive the gas moving device.

Controlling the at least the gas moving device's operations and theoxygen delivery module's operations may include determining energysource used to power the oxygen delivery module and the gas movingdevice, and causing the pressure resulting from the operation of the gasmoving device to be substantially at the pre-determined pressure valueand causing the purity level of the oxygen produced by the oxygendelivery module to be substantially at the pre-determined purity valuein response to a determination that the energy source is a battery.

In a further aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module to produce at leastconcentrated oxygen, a controller configured to control the oxygendelivery module to cause the oxygen delivery module to deliver oxygen toa patient based on a patient's tidal volume data representative of thenormal volume of air displaced between inspiration and expiration by thepatient, and further based on a fraction of inspired oxygen (FiO2) valuerequired for the patient.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any of the followingfeatures.

The controller may further be configured to determine operatingconditions for the oxygen delivery device based on the patient's tidalvolume and the required FiO2, and further based on one or more of, forexample, respiratory rate for the patient, oxygen purity value of theoxygen delivered to the patient, and/or Inspiration:Expiration (I:E)ratio.

The operating conditions include one or more of, for example, speed ofthe gas moving device providing an air flow to the oxygen deliverymodule, oxygen delivery module cycle speed, and/or desired oxygen puritylevel to be produced by the oxygen delivery device.

The controller configured to determine operating conditions may beconfigured to determine optimal operating conditions that would resultin reduced energy consumption for the system.

The device may further include one or more of, for example, a pressuresensor to determine a pressure level produced by oxygen delivery device,a gas moving device providing an air flow to the oxygen delivery module,and/or a purity sensor to determine oxygen purity value produced by theoxygen delivery device.

In yet another aspect, a method is disclosed. The method includesreceiving data representative of at least a patient's tidal volume dataindicative of normal volume of air displaced between inspiration andexpiration by the patient, and data representative of a fraction ofinspired oxygen (FiO2) value required for the patient, and controllingan oxygen delivery module producing at least concentrated oxygen tocause the oxygen delivery module to deliver oxygen to the patient basedat least on the patient's tidal volume data and the FiO2 value.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods.

In another aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module, at least one sensorto detect patient breathing, and a controller configured to control theoxygen delivery module to cause the oxygen delivery module to deliveroxygen to the patient based on data from the at least one sensor suchthat in response to a determination, based on data from the at least onesensor, that no breathing is detected for a first pre-determined periodof time, the controller causes the oxygen delivery module to deliveroxygen to the patient in continuous flow mode, and in response to adetermination, based on additional data from the at least one sensor,that breathing is detected for a second period of time, the controllercauses the oxygen delivery module to deliver oxygen to the patient in apulse flow mode.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any one of the followingfeatures.

The at least one sensor may be configured to detect patient breathing byperforming one of, for example, continuous detection of patientbreathing, and/or periodic detection of patient breathing.

The controller may further be configured, subsequent to thedetermination that no breathing is detected and to causing the oxygendelivery module to deliver oxygen to the patient in continuous flowmode, to terminate the continuous flow delivery of oxygen to thepatient, and cause the oxygen delivery module to deliver oxygen to thepatient in pulse dose mode in response to one or more of, for example, adetermination that a second pre-determined period of time has elapsedsince the determination that no breathing is detected, and thedetermination, based on the additional data from the at least onesensor, that the patient is breathing.

The at least one sensor may include a pressure sensor fluidly connectedto a cannula coupled to the oxygen delivery module, the cannulastructured to deliver the oxygen from the oxygen delivery module throughthe patient's nasal passages.

The pressure sensor fluidly connected to the cannula may be configuredto detect pressure changes within the patient's nasal passages, and togenerate data representative of the pressure changes.

The controller may further be configured to receive a feed of the datagenerated by the pressure sensor, and perform filtering operation on thefeed of the data generated by the pressure sensor to determine onset ofan inspiratory cycle for the patient.

In an additional aspect, a method is disclosed. The method includesreceiving information regarding patient breathing, and controllingoxygen delivery to a patient by causing an oxygen delivery module todeliver oxygen to the patient in continuous mode flow in response to adetermination, based on the received information, that no patientbreathing is detected for a first pre-determined period of time and inresponse to a determination, based on data from the at least one sensor,that breathing is detected for a second period of time, the controllercauses the oxygen delivery module to deliver oxygen to the patient in apulse flow mode.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any of the followingfeatures.

Controlling the oxygen delivery may include, subsequent to causing theoxygen delivery module to deliver oxygen to the patient in continuousflow mode in response to the determination that no breathing isdetected, terminating the continuous flow delivery of oxygen to thepatient, and causing the oxygen delivery module to deliver oxygen to thepatient in pulse dose mode in response to one or more of, for example,determining that a second pre-determined period of time has elapsedsince the determination that no breathing is detected, and/ordetermining, based on additionally received information, that thepatient is breathing.

In another aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module, and one or moresensors to determine data representative of one or more of environmentalconditions, operating conditions of the oxygen delivery device, andpatient's characteristics. The oxygen delivery device also includes acontroller to control, based at least in part on the determined data, atleast the oxygen delivery module's operations, and a display module topresent information based, at least in part, on the data representativeof the characteristics of the patient.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any one of the followingfeatures.

The one or more sensors may include one or more of, for example, anelectroencephalogram, an electrooculogram, an electrocardiogram, anactigraph, a pedometer, a pulse oximeter, an accelerometer, a pressuresensor, a flow sensor, a purity sensor, a clock, and/or a timer.

The display module may include a touch screen.

The display module may include discrete buttons adjacent to a displayarea.

The information presented may include one or more of, for example,patient's sleep state, patient's respiratory rate,inspiratory:expiratory time ratio, ambulation time, activity level,oxygen saturation, total oxygen delivered, heart rate, oxygen deliveredper period of time, hours of usage, and/or usage time. The informationdisplayed may further include trends of the available information.

The oxygen delivery device may further include a communication module tocommunicate data to a remote location using one or more of, for example,a wireless communication link, and/or a wired-based communication link.

In a further aspect, an oxygen delivery device is disclosed. The deviceincludes an oxygen delivery module, one or more sensors to determinedata representative of one or more of, for example, environmentalconditions, operating conditions of the oxygen delivery device, and/orpatient's characteristics, a controller to control, based at least inpart on the determined data, at least the oxygen delivery module'soperations, and an identification module to receive informationrepresentative of an identity of a user and to compare the receivedinformation to stored data uniquely identifying a patient associatedwith the oxygen delivery device.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any one of the followingfeatures.

The identification module may include one or more of, for example, analpha-numeric keypad, an iris scanner, a magnetic stripe card, a barcodescanner, a fingerprint scanner, a facial feature recognition device,and/or a palm scanner.

The controller may associate patient identification with data collectedby the one or more sensors.

Data collected by the one or more sensors may be used to compute one ormore of, for example, sleep state, respiratory rate,inspiratory:expiratory time ratio, ambulation time, activity level,oxygen saturation, total oxygen delivered, heart rate, oxygen deliveredper period of time, hours of usage, and/or usage time.

In another aspect, an oxygen delivery device is disclosed. The deviceincludes an oxygen delivery module, one or more sensors to determinedata representative of one or more of, for example, environmentalconditions, operating conditions of the oxygen delivery device, and/orpatient's characteristics, a controller to control, based at least inpart on the determined data, at least the oxygen delivery module'soperations, and an identification module to receive informationrepresentative of an identity of a user and to compare the receivedinformation to stored data uniquely identifying a patient associatedwith the portable oxygen delivery device. The device also includes adisplay module to present information based, at least in part, on datadetermined by the one or more sensors.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any of the followingfeatures.

The information displayed may further include trends of the availableinformation.

The controller may associate patient identification with data collectedby the one or more sensors.

The controller may further be configured to compare the determined datarepresentative of the one or more of, for example, the environmentalconditions, the operating conditions of the oxygen delivery device,and/or the patient's characteristics, to respective pre-determinedthreshold values representative of one or more of normal environmentalconditions, normal operating conditions of the oxygen delivery device,and normal patient's characteristics, and communicate an alert inresponse to a determination that at least one of the determined datarepresentative of the one or more of the environmental conditions, theoperating conditions of the oxygen delivery device, and the patient'scharacteristics, deviates from a respective at least one of thepre-determined threshold values representative of one or more of normalenvironmental conditions, normal operating conditions of the oxygendelivery device, and normal patient's characteristics.

The display device may be configured to present information based, atleast in part, on the data determined by the one or more sensors inresponse to a determination by the identification module that the datadetermined by the one or more sensor corresponds to the patientidentified by the identification module.

In yet another aspect, an oxygen delivery device is disclosed. Theoxygen delivery device includes an oxygen delivery module configured todeliver a pulse including greater than 100 mL of concentrated oxygen,and a controller configured to control the oxygen delivery module tocause the oxygen delivery module to deliver the pulse including greaterthan the 100 mL of the concentrated oxygen within approximately first60% of a patient's inspiratory period.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any of the followingfeatures.

The oxygen delivery device may further includes at least one sensor todetect patient breathing. The controller is configured to control theoxygen delivery module to cause the oxygen delivery module to deliverthe pulse of the at least 100 mL of concentrated oxygen upon adetermination, based on data received from the at least one sensor, thatthe patient's inspiratory cycle has commenced. The at least one sensormay include a pressure sensor fluidly connected to a cannula coupled tothe oxygen delivery module, the cannula structured to deliver the oxygenfrom the oxygen delivery module through the patient's nasal passages.The pressure sensor fluidly connected to the cannula may be configuredto detect pressure changes within the patient's nasal passages, and togenerate data representative of the detected pressure changes.

The controller may further be configured to receive a feed of the datagenerated by the at least one sensor, and to perform filtering operationon the feed of the data generated by the at least one sensor todetermine onset of an inspiratory cycle for the patient.

The oxygen delivery module configured to deliver the pulse greater than100 mL may be configured to deliver a pulse of between 100 mL and 270 mLof concentrated oxygen.

In an additional aspect, a method is disclosed. The method includescontrolling an oxygen delivery module to cause the oxygen deliverymodule to deliver a pulse greater than 100 mL of concentrated oxygen,and delivering by the oxygen delivery module the pulse including greaterthan 100 mL of concentrated oxygen within approximately first 60% of apatient's inspiratory period.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods.

In a further aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module to provide at leastconcentrated oxygen, a piezoelectric valve coupled to an output of theoxygen delivery module to receive the produced concentrated oxygen, adriver to electrically actuate the piezoelectric valve, and a controllerto control the driver to cause controllable actuation of thepiezoelectric valve by the driver so as to cause controllable opening ofthe valve to enable flow of oxygen delivered by the oxygen deliverymodule to be directed for inhalation by a patient via the piezoelectricvalve.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any of the followingfeatures.

The oxygen delivery device may further include one or more sensors todetermine data representative of one or more of, for example,environmental conditions, operating conditions of the oxygen deliverydevice, and/or the patient's therapeutic conditions. The controllerconfigured to control the driver to cause controllable actuation of thepiezoelectric valve may be configured to control the driver to causecontrollable actuation of the piezoelectric valve based, at least inpart, on the determined data from the one or more sensors representativeof the one or more of environmental conditions, operating conditions ofthe oxygen delivery device, and patient's therapeutic conditions.

In another aspect, a method is disclosed. The method includesdetermining data representative of one or more of environmentalconditions, operating conditions of an oxygen delivery device, and apatient's therapeutic conditions, and controlling a driver actuating apiezoelectric valve coupled to an output of an oxygen delivery module ofan oxygen delivery device based, at least in part, on the determineddata from the one or more sensors representative of the one or more ofthe environmental conditions, the operating conditions of the oxygendelivery device, and the patient's therapeutic conditions, to causecontrollable opening of the valve to enable flow of oxygen delivered bythe oxygen delivery module to be directed for inhalation by the patientvia the piezoelectric valve.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods.

In yet a further aspect, an oxygen delivery device is disclosed. Theoxygen delivery device includes an oxygen delivery module to produce atleast concentrated oxygen, and a gas moving device to deliver air to theoxygen delivery module. The gas moving device includes at least onepiston rotatable inside a first chamber defined in a housing, therotational movement of the at least one piston inside the first chamberresulting in varying pressure generated in a first portion of the firstchamber, and a vane member rigidly coupled to the at least one piston,the vane member being configured to move inside a vane chamber definedin the housing. The piston and the vane rigidly coupled to the pistondefine the first portion of the first chamber and a second portion ofthe first chamber.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any one of the followingfeatures.

The at least one rotatable piston may define a radial clearance betweentangential surfaces of the at least one rotatable piston and the firstchamber wall surface, the clearance being less than or equal to 50microns.

The varying pressure resulting in the first chamber may be representedas a first periodic function of the pressure generated in the firstportion of the first chamber.

The gas moving device may be configured as one or more of, for example,a compressor, and/or a vacuum pump.

The oxygen delivery device may further include at least one additionalgas moving device. Each of the additional gas moving device may includea corresponding additional piston rotating inside a corresponding borechamber defined in the housing, the rotational movement of thecorresponding additional piston inside the corresponding bore chamberresulting in corresponding pressure represented as a correspondingadditional periodic function created in a corresponding portion of thecorresponding bore chamber. The each of the additional gas moving devicemay include a corresponding additional vane member coupled to thecorresponding additional piston, the corresponding additional vane beingconfigured to move inside a corresponding additional vane chamberdefined in the housing.

The at least one additional gas moving device may include two, three, orfour gas moving devices. The at least one additional gas moving devicemay all be driven by a single rotary power source.

Forces resulting from the rotational movement of the at least one pistonin the first chamber may destructively interfere with forces resultingfrom the rotational movement of the corresponding additional piston ofeach of the at least one additional gas moving device in thecorresponding bore chamber, such that net forces created in the oxygendelivery device are reduced.

The housing may include axially separated surfaces, and one or moreendplates effectively sealing the first chamber. The at least one pistonmay include a cylindrical piston with an exterior diameter, thecylindrical piston being operatively associated with a drive memberdisposed within the first chamber and rotatable therein, and furtherbeing offset with respect to a centerline of the first chamber portionsuch that the exterior diameter of the piston is in close proximity tobounds of the first chamber portion during orbit of the piston, todivide the first chamber into a suction chamber portion and acompression chamber portion.

The oxygen delivery device may have a weight of between 2-15 pounds.

The at least one piston rotating inside the first chamber of the housingmay include a first piston rotating inside the first chamber tofacilitate compression operations, and a second, separate pistonrotating inside a second chamber defined in the housing to facilitatevacuum pump operations. Compressor pressure generated in the firstchamber may be represented as a first sinusoidal function, and pressureformed in the second chamber may be represented as a second sinusoidalfunction that is approximately 180° out of phase relative to the firstsinusoidal function. The relative radial position of the first piston inthe first chamber may be represented as a first periodic function, andthe relative radial position of the second piston in the second chambermay be represented as a second periodic function that is out of phase inrelation to the first periodic function.

Forces resulting from the rotational movement of the first piston in thefirst chamber may destructively interfere with forces resulting from therotational movement of the second piston in the second chamber such thatnet forces created in the oxygen delivery device are reduced.

In another aspect, a method is disclosed. The method includes supplyingair to a gas moving device configured to deliver compressed air to anoxygen delivery module of an oxygen delivery device, actuating at leastone piston rotatable inside a first chamber defined in the housing ofthe gas moving device, the rotational movement of the at least onepiston inside the first chamber resulting in varying pressure generatedin a first portion of the first chamber. The at least one piston isrigidly coupled to a vane member configured to move inside a vanechamber defined in the housing, the piston and the vane rigidly coupledto the piston define the first portion of the first chamber and a secondportion of the first chamber. The method also includes directingpressured air from the first chamber to the oxygen delivery module.

Embodiments of the method device may include any of the featuresdescribed in the present disclosure, including any of the featuresdescribed above in relation to the devices and methods, as well as anyof the following features.

Actuating the at least one piston rotatable inside the first chamber mayinclude actuating a first piston rotatable inside the first chamberconfigured to operate as a compressor to draw ambient air into theoxygen delivery module, the rotational movement of the at least onepiston inside the first chamber resulting in compressor pressure createdin the first chamber that is represented as a first periodic function,and may also includes actuating a second piston inside a second chamberof the housing, the second chamber configured to operate as a vacuumpump to draw exhaust gas from the oxygen delivery module, the rotationalmovement of the second piston inside the second chamber resulting invacuum pump pressure created in the second chamber that is representedas a second periodic function. The first periodic functionrepresentative of the compressor pressure inside the first chamber maybe approximately 180° out of phase relative to the second periodicfunction representative of the vacuum pump pressure created inside thesecond chamber such that forces resulting from the rotational movementof the first piston in the first chamber destructively interfere withforces resulting from the rotational movement of the second piston inthe second chamber.

In an additional aspect, an oxygen delivery device is disclosed. Theoxygen delivery device includes an oxygen delivery module to produce atleast concentrated oxygen, a first gas moving device to deliver air tothe oxygen delivery module, the first gas moving device being driven bya first motor to actuate the gas moving device to run at variablespeeds. The device also includes a second gas moving device to drawexhaust gas from the oxygen delivery module, the second gas movingdevice being driven by a second motor, separate from the first motor, toactuate the second gas moving device to run at variable speeds.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any of the followingfeatures.

The oxygen delivery device may further include at least one sensor todetermine data representative of one or more of, for example,environmental conditions, operating conditions of the oxygen deliverydevice, and/or patient's therapeutic conditions. The device may alsoinclude at least one controller to control the speeds of at least one ofthe first gas moving device and the second gas moving device bycontrolling operations of at least the first motor and the separatesecond motor based on the determined data.

The determined data may include data representative of one or more of,for example, oxygen flow, ambient pressure, ambient temperature, and/orrequired oxygen purity.

In a further aspect an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module, at least one sensorto determine at least one environmental condition in which the portableoxygen delivery device is operating, and a controller to control, basedon the determined at least one environmental condition, at least theoxygen delivery module's operations to cause a specified therapeuticrequirement for the patient to be achieved.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well the following features.

The at least one sensor may be configured to determine one or more of,for example, ambient temperature, and/or altitude.

In another aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module to produce at leastconcentrated oxygen, a first gas moving device to deliver air to anoxygen delivery module, the first gas moving device being driven by afirst motor to actuate the gas moving device to run at variable speeds.The device also includes a second gas moving device to draw exhaust gasfrom the oxygen delivery module, the second gas moving device beingdriven by a second motor, separate from the first motor, to actuate thesecond gas moving device to run at variable speeds, a purity sensor todetermine oxygen purity value produced by the oxygen delivery module,and a controller to control speeds of the first and second gas movingdevices by controlling operations of at least the first motor and theseparate second motor, based at least in part on the determined oxygenpurity value, to cause the purity level of the oxygen produced by theoxygen delivery module to be substantially at a pre-determined purityvalue.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as the following features.

The pre-determined purity value may be the minimum acceptable oxygenpurity level to enable energy consumption of the system to be reduced,the pre-determined purity value having a value of between approximately82% and approximately 93% of oxygen.

In an additional aspect, an oxygen delivery device is disclosed. Theoxygen delivery device includes an oxygen delivery module to produce atleast concentrated oxygen, and a controller to control at least someoperations of the oxygen delivery device, including controllingoperation affecting operations of the oxygen delivery module, thecontroller configured to enable the activation of one or more of aplurality of operational modes supported by the oxygen delivery device.The controller includes at least one processor based device, and atleast one non-transitory memory storage device to store computerinstructions, the computer instructions including instructions that whenexecuted on the at least one processor-based device cause the at leastone processor-based device to receive data indicative of one or moreoperational modes from the plurality of operational modes that are to beactivated, and in response to the received data, enabling the one ormore operational modes of the oxygen delivery device that are to beactivated.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any of the followingfeatures.

The computer instructions that cause the at least one processor-baseddevice to receive the data indicative of the one or more operationalmodes may include further instructions that further cause the at leastone processor-based device to receive data indicative of at least oneactive operational mode that is to be disabled.

The controller may be configured to cause the oxygen delivery device tooperate in a default generic mode when all other of the plurality ofoperational modes are not active.

In yet a further aspect, a method is disclosed. The method includesreceiving data indicative of one or more operational modes, from aplurality of operational modes supported by an oxygen delivery device,that are to be activated, enabling the operational modes that are to beactivated based on the received data, and controlling at least someoperations of the oxygen delivery device, including controllingoperation affecting operations of an oxygen delivery module to produceat least concentrated oxygen, based on the enabled operational modes.

Embodiments of the method device may include any of the featuresdescribed in the present disclosure, including any of the featuresdescribed above in relation to the devices and methods.

In an additional aspect, an oxygen concentrator system is disclosed. Thesystem includes a cart, and an oxygen delivery device placed on thecart. The oxygen delivery device includes an oxygen delivery module, atleast one sensor to measure data representative of at least one patientcharacteristic, the at least one sensor being secured to the cart. Theoxygen delivery device further includes a controller to receive themeasured data and monitor the at least one patient characteristic basedon the received measured data.

Embodiments of the system may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices and methods, as well as any of the followingfeatures.

The at least one sensor may be secured to a handle of the cart such thatthe at least one sensor is configured to measure the data representativeof the at least one patient characteristic while the patient is graspingthe handle.

The at least one sensor may include one or more of, for example anoximeter to measure the patient's SpO2 level, and/or a pedometer tomeasure the patient's activity level.

The controller may further be configured to compare the measured datarepresentative of the at least one patient characteristic to arespective at least one pre-determined threshold value representative ofnormal values for the corresponding at least one patient characteristic,and communicate an alert in response to a determination that themeasured data representative of the at least one patient characteristicdeviates from the respective at least one pre-determined threshold valuerepresentative of the normal values corresponding at least one patientcharacteristic.

In another aspect, a method is disclosed. The method includes measuringdata representative of at least one patient characteristic using atleast one sensor secured to a cart on which an oxygen delivery device isplaced, receiving the measured data representative of the at least onepatient characteristic, and monitoring the at least one patientcharacteristic based on the received measured data.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, as well as any of thefollowing features.

In another aspect, a respiratory device is disclosed. The respiratorydevice includes an oxygen delivery device including an oxygen deliverymodule to produce at least concentrated oxygen, and a gas moving deviceto deliver air to the oxygen delivery module, the gas moving devicebeing driven by a motor to actuate the gas moving device. Therespiratory device also includes a nebulizer containing liquidmedication for a patient that is stored in a medication chamber definedwithin the nebulizer, the nebulizer being coupled to the oxygen deliverydevice such that the concentrated oxygen produced by the oxygen deliverymodule is directed into the inner medication chamber of the nebulizer toconvert at least some of the liquid medication into aerosol medication.At least some of the concentrated oxygen directed into the nebulizer andthe at least some of the converted aerosol medication are delivered forinhalation by a patient through a nebulizer outlet port.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, as well as any of thefollowing features.

The nebulizer may be coupled to the oxygen delivery module through atubing connecting the nebulizer to an outlet of the oxygen deliverydevice through which the oxygen produced by the oxygen delivery moduleis delivered.

The nebulizer may include a jet nebulizer configured to use theconcentrated oxygen directed into the nebulizer at high velocity as agas source to cause the liquid medication to be concerted to aerosol.

The liquid medication may include one or more of, for example, liquidmedication to treat cystic fibrosis, liquid medication to treat asthma,and/or liquid medication to treat other respiratory diseases.

In an additional aspect, a method is disclosed. The method includesproducing concentrated oxygen using an oxygen delivery device includingan oxygen delivery module to produce at least the concentrated oxygen,and a gas moving device to deliver air to the oxygen delivery module,converting at least some of liquid medication contained in a medicationchamber of a nebulizer into aerosol medication by directing theconcentrated oxygen produced by the oxygen delivery module into thenebulizer, and delivering at least some of the concentrated oxygendirected into the nebulizer and at least some of the converted aerosolmedication for inhalation by a patient through a nebulizer outlet port.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods.

In a further aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery device including an oxygendelivery module to produce at least concentrated oxygen, and a gasmoving device to deliver air to the oxygen delivery module, the gasmoving device being driven by a motor to actuate the gas moving device.The device also includes a container holding fluid, the container beingcoupled to the oxygen delivery device such that the concentrated oxygenproduced by the oxygen delivery module is directed into the container tobe passed through the fluid so as to entrain at least some fluid vapor.At least some of the concentrated oxygen directed into the container andthe fluid vapor are delivered for inhalation by a patient through anoutlet of the container.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, as well as any one of thefollowing features.

The container may be coupled to the oxygen delivery device through atubing connecting the container to an outlet of the oxygen deliverydevice through which the oxygen produced by the oxygen delivery moduleis delivered.

The fluid in the container may include scented fluid. The entrainedfluid vapor may include entrained scented fluid vapor used to performone or more of, for example, encouraging patient compliance with oxygentherapy, providing respiratory disinfection, providing decongestion,providing expectoration, and/or providing beneficial psychologicaltreatment to the patient.

The fluid in the container may include water. The entrained fluid vapormay include entrained water vapor to facilitate humidifyingfunctionality.

In yet another aspect, a method is disclosed. The method includesproducing concentrated oxygen using an oxygen delivery device includingan oxygen delivery module to produce at least the concentrated oxygen,and a gas moving device to deliver ambient air to the oxygen deliverymodule. The method also includes directing the concentrated oxygenthrough fluid in a container to entrain at least some of fluid intofluid vapor, and delivering at least some of the concentrated oxygendirected into the fluid container and the entrained fluid vapor forinhalation by a patient through an outlet of the container.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, as well as the followingfeature.

The fluid may include one of, for example, scented fluid, and/or water.

In another aspect, an oxygen delivery device is disclosed. The deviceincludes an oxygen delivery module to produce at least concentratedoxygen, the oxygen delivery module including one or more adsorbent bedsconfigured to selectively adsorb corresponding materials from fluiddirected through the one or more adsorbent beds, a rotary valve forselectively transferring the fluid through the one or more adsorbentbeds, and one or more position sensors to determine a valuerepresentative of the rotational position of the rotary valve. Thedevice further includes a controller configured to, in response totermination of operation of the oxygen delivery module, cause actuationof the rotary valve, based on the data determined by the one or moreposition sensors, to rotate the rotary valve to a position wherepassages between ambient air and the one or more adsorbent beds areclosed so as to prevent atmospheric moisture from reaching the one ormore adsorbent beds.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, as well as any of thefollowing features.

The one or more position sensors may include at least one of, forexample, a rotary encoder, and/or a shaft position indicator. The one ormore position sensors may be placed proximate one or more of, forexample, the rotary valve, and/or a shaft coupled to the rotary valve.

The rotary valve may include a rotary valve shoe and a valve port platehaving respective engaged surfaces and the rotary valve shoe rotatableto provide valving action for selectively transferring fluidstherethrough, the rotary valve shoe including multiple passages allowingfluid to flow therethrough, and a fluid distribution manifold todistribute fluids between the adsorption beds and the valve members, thefluid distribution manifold including multiple passages allowing fluidto flow therethrough. The rotary valve may also includes one or morepassages of at least one of the rotary valve shoe and the fluiddistribution manifold including one or more purge passages having adistinct flow control element disposed therein other than the at leastone or more passages of at least one of the rotary valve shoe and thefluid distribution manifold to allow for precise control of purge fluidtherethrough to improve pressure swing adsorption system performance.

In a further aspect, a method is disclosed. The method includesdetermining rotary position of a rotary valve for an oxygen deliverymodule using one or more position sensors, the rotary valve configuredto selectively transfer fluid through the one or more adsorbent bedsthat selectively adsorb corresponding materials from the fluid. Inresponse to termination of operation the oxygen delivery module,controllably actuating the rotary valve, based on the data determined bythe one or more position sensors, to rotate the rotary valve to aposition where passages between ambient air and the one or moreadsorbent beds are closed so as to prevent atmospheric moisture fromreaching the one or more adsorbent beds.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods.

In another aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module, at least one sensorto determine data representative of performance degradation of one ormore filters used with the oxygen delivery device, and a controller toalert, based on the determined data representative of the performancedegradation of the one or more filters, that performance of at least oneof the one or more filters has degraded.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, as well as any of thefollowing features.

The one or more filters may include an intake filter to filter ambientair drawn into a gas moving device, wherein the at least one sensor isconfigured to determine pressure differential across the intake filter.The controller may be configured to alert that performance of the atleast one of the one or more filters has degraded is configured to alertthat the performance of the intake filter has degraded in response to adetermination that the determined pressure differential across theintake filter exceeds a pre-determined pressure differential threshold.

In an additional aspect, a method is disclosed. The method includesmeasuring pressure differential across an intake filter configured tofilter ambient air drawn into a gas moving device, determining whetherthe measured pressure differential across the intake filter exceeds apre-determined pressure differential threshold, and alerting thatperformance of the intake filter had degraded in response to adetermination that the measured pressure differential across the intakefilter exceeds the pre-determined pressure differential threshold.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods.

In yet a further aspect, an oxygen delivery device is disclosed. Theoxygen delivery device includes an oxygen delivery module to produce atleast concentrated oxygen, and a controller to perform one or more ofcontrolling at least some operations of the oxygen delivery device,identifying problems associated with the oxygen delivery device,resolving the identified problems associated with the oxygen deliverydevice, and calibrating the oxygen delivery device. The controllerincludes at least one processor based device, and at least onenon-transitory memory storage device to store computer instructions, thecomputer instructions including instructions that when executed on theat least one processor-based device cause the at least oneprocessor-based device to receive data representative of operation ofthe oxygen delivery device; and determine automatically problemsassociated with the operations of the oxygen delivery device based onthe received data.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, as well as any of thefollowing features.

The computer instructions that cause the at least one processor baseddevice to determine automatically problems associated with theoperations of the oxygen delivery device may include instructions thatcause the at least one processor-based device to determine automaticallyproblems associated with the operations of the oxygen delivery deviceusing an expert system learning engine.

The instructions may further include instruction to further cause the atleast one processor based device to automatically determine data tocontrollably change one or more operation parameters of the oxygendelivery device to cause a change in the operation of the respiratorycare device, and change the operation parameters of the oxygen deliverydevice according to the determined data.

In an additional aspect, an oxygen delivery device is disclosed. Theoxygen delivery device includes an oxygen delivery module to produce atleast concentrated oxygen, and a tracking device coupled to the oxygendelivery device to enable determining geographical location of theoxygen delivery device. The tracking device includes one or more of, forexample, a) a WiFi-based geolocation device including a wireless receiveconfigured to determine availability of WiFi-based network routers inthe vicinity of the oxygen delivery device, and to communicate with oneor more of the WiFi-based network routers available in the vicinity ofthe oxygen delivery device, wherein an approximation of the geographicallocation of the oxygen delivery device is determined based on locationdata associated with the one or more WiFi-based network routerscommunicating with the oxygen delivery device, b) a GPS-based trackingdevice to receive GPS signals from one or more satellite, determineapproximate position of the GPS-tracking device based on the receivedGPS signals, and communicate to a remote location data representative ofthe determined the approximate position of the GPS-tracking device, andc) a device to monitor use of the oxygen delivery device, and to causean alarm to be activated in response to a determination that the oxygendelivery device was not used for at least a pre-determined period oftime.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, as well as the followingfeatures.

The device to monitor use of the oxygen delivery device may include a PCboard mounted within the oxygen delivery device.

In a further aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module to produce at leastconcentrated oxygen, at least one sensor to determine datarepresentative of one or more of environmental conditions, operatingconditions of the oxygen delivery device, and patient's therapeuticconditions, and a controller. The controller is configured tocommunicate the determined data to a remote station to facilitatedetermining values of operation parameters controlling operation of theoxygen delivery device based on, at least in part, the communicated datarepresentative of the one or more of the environmental conditions, theoperating conditions of the oxygen delivery device, and the patient'stherapeutic conditions, receive from the remote station datarepresentative of the values of the operation parameters controllingoperation of the oxygen delivery device, and adjust the operationparameters of the oxygen delivery device based on the data received fromthe remote station.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods.

In another aspect, a method is disclosed. The method includesdetermining data representative of one or more of environmentalconditions, operating conditions of an oxygen delivery device comprisingan oxygen delivery module to produce at least concentrated oxygen, andpatient's therapeutic conditions, and communicating the determined datato a remote station to facilitate determining values of operationparameters controlling operation of the oxygen delivery device based on,at least in part, the communicated data representative of the one ormore of the environmental conditions, the operating conditions of theoxygen delivery device, and the patient's therapeutic conditions. Themethod also includes receiving from the remote station operationparameter data representative of the values of the operation parametersto control operation of the oxygen delivery device, and adjusting theoperation parameters of the oxygen delivery device based on the datareceived from the remote station.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods.

In yet another aspect, an oxygen delivery device is disclosed. Theoxygen delivery device includes an oxygen delivery module to produce atleast concentrated oxygen, a purity sensor to determine oxygen purityvalue produced by the oxygen delivery module, one or more device sensorsto monitor the operation of the oxygen delivery device, and acontroller. The controller is configured to receive data from the puritysensor and the one or more device sensors, determine, based on the datareceived from the one or more device sensors, whether an operationalproblem condition exists in relation to the operation of the oxygendelivery device, and in response to a determination that a problemcondition exists in relation to the operation of the oxygen deliverydevice, cause at least partial operation of the oxygen delivery deviceto be maintained upon a further determination, based on the datareceived from the purity sensor, that the oxygen purity level exceeds apre-determined minimum purity threshold.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, including any of thefollowing features.

The pre-determined minimum purity threshold may be 21%.

The controller may be configured to cause the at least partial operationof the oxygen delivery device to be maintained is configured to cause achange from an operation mode that was active before the determinationthat a problem condition exists to another operational mode for theoxygen delivery device.

In an additional aspect, a method is disclosed. The method includesreceiving data from a purity sensor representative of the oxygen puritylevel of oxygen produced by an oxygen delivery module of an oxygendelivery device, receiving data from one or more device sensorsmonitoring the operation of the oxygen delivery device, determining,based on the data received from the one or more device sensors, whetheran operational problem condition exists in relation to the operation ofthe oxygen delivery device, and in response to a determination that aproblem condition exists in relation to the operation of the oxygendelivery device, causing at least partial operation of the oxygendelivery device to be maintained upon a further determination, based onthe data received from the purity sensor, that the oxygen purity levelexceeds a pre-determined minimum purity threshold.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods.

In a further aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module to produce at leastconcentrated oxygen, a gas moving device to deliver the ambient air tothe oxygen delivery module, a stepper motor comprising one or moreelectromagnetic coils arranged around a gear element, the stepper motorconfigured to drive at least the gas moving device, and a controllerconfigured to modulate the driving signals used to energize the one ormore electromagnetic coils to achieve a specified slew rate so as toreduce the vibration and structural noise emanating from the steppermotor without loss of efficiency.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods.

In yet another aspect, an oxygen delivery device is disclosed. Theoxygen delivery device includes an oxygen delivery module to produce atleast concentrated oxygen, the oxygen delivery module including one ormore adsorbent beds configured to selectively adsorb correspondingmaterials from fluid directed through the one or more adsorbent beds, arotary valve for selectively transferring the fluid through the one ormore adsorbent beds, the rotary valve including an index indicatordetectable by a sensor, and one or more sensors to detect the indexingindicator on the rotary valve. The oxygen delivery device furtherincludes a controller configured to determine from information relatingto the indexing indicator detected by the one or more sensors at leastone of: rotational position of rotary valve, and number of rotationcycles completed by the rotary valve during a pre-determined period oftime.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, including any one of thefollowing features.

The controller may be further configured to cause actuation of therotary valve, based on the rotational position of the rotary valvedetermined from the information relation to the detected indexingindicator, to rotate the rotary valve to a position where passagesbetween ambient air and the one or more adsorbent beds are closed so asto prevent atmospheric moisture from reaching the one or more adsorbentbeds.

The rotary valve may include a rotary valve shoe and a valve port platehaving respective engaged surfaces and the rotary valve shoe rotatableto provide valving action for selectively transferring fluidstherethrough, the rotary valve shoe including multiple passages allowingfluid to flow therethrough, a fluid distribution manifold to distributefluids between the adsorption beds and the valve members, the fluiddistribution manifold including multiple passages allowing fluid to flowtherethrough, and one or more passages of at least one of the rotaryvalve shoe and the fluid distribution manifold including one or morepurge passages having a distinct flow control element disposed thereinother than the at least one or more passages of at least one of therotary valve shoe and the fluid distribution manifold to allow forprecise control of purge fluid therethrough to improve pressure swingadsorption system performance.

The sensor may include a switch configured to be activated when theindexing indicator passes the switch, and to generate a signal to thecontroller indicative that the indexing indicator has passed the switch.

The switch may include one or more of, for example, an optical switch tooptically detect the indexing indicator when the indexing indicatorpasses by the optical switch, and/or a mechanical switch configured tobe mechanically activated upon mechanical actuation of the switch by theindexing indicator.

In a further aspect, a method is disclosed. The method includesdetecting an indexing indicator included on a rotary valve for an oxygendelivery module using one or more sensors, the rotary valve configuredto selectively transfer fluid through the one or more adsorbent bedsthat selectively adsorb corresponding materials from the fluid, anddetermining based on information relating to the indexing indicatordetected by the one or more sensors at least one of, for example,rotational position of rotary valve, and/or number of rotation cyclescompleted by the rotary valve during a pre-determined period of time.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods.

In an additional aspect, an oxygen delivery device is disclosed. Thedevice includes an oxygen delivery module to produce at leastconcentrated oxygen, a gas moving device to deliver the ambient air tothe oxygen delivery module, a fan to cool the oxygen delivery device, atleast one temperature sensor, and one or more sensors to determine datarepresentative of one or more of environmental conditions, operatingconditions of the oxygen delivery device, and a patient's therapeuticconditions, including at least one temperature sensor to measuretemperature of the oxygen delivery device. The oxygen delivery devicefurther includes a controller to control operation of the fan based onthe data determined by the one or more sensors, including thetemperature measured by the temperature sensor, to control the fan tocause the temperature of the oxygen delivery device to be at an optimaltemperature at which power consumption of the oxygen delivery device fora particular set of performance requirements is optimized.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, including any one of thefollowing features.

The particular set of performance requirements includes a particularoxygen purity level of oxygen produced by the oxygen delivery module,and a particular fraction of inspired oxygen (FiO2) value required forthe patient.

The controller may further be configured to determine the optimaltemperature at which the power consumption of the oxygen delivery devicefor the particular set of performance requirements is optimized byvarying fan speed in discrete steps over an interval of time, at eachvaried fan speed value, determining the corresponding temperature andcorresponding power consumption at the corresponding temperature, andidentifying the temperature that resulted in the minimal powerconsumption.

In another aspect, a method is disclosed. The method includesdetermining data representative of one or more of environmentalconditions, operating conditions of an oxygen delivery device, and apatient's therapeutic conditions, including at least one temperaturesensor to measure temperature of the oxygen delivery device, andcontrolling operation of a fan, configured to cool the oxygen deliverydevice, based on the data determined by the one or more sensors,including the temperature measured by the temperature sensor, so as tocause the temperature of the oxygen delivery device to be at an optimaltemperature at which power consumption of the oxygen delivery device fora particular set of performance requirements is optimized.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, including the followingfeature.

Controlling operation of the fan may include determining the optimaltemperature at which the power consumption of the oxygen delivery devicefor the particular set of performance requirements is optimized byvarying fan speed in discrete steps over an interval of time, at eachvaried fan speed value, determining the corresponding temperature andcorresponding power consumption at the corresponding temperature, andidentifying the temperature that resulted in the minimal powerconsumption.

In a further aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module to produce at leastconcentrated oxygen, a first gas moving device to deliver air to theoxygen delivery module, the first gas moving device being driven by afirst motor to actuate the first gas moving device, and a second gasmoving device to draw exhaust gas from the oxygen delivery module, thesecond gas moving device being driven by a second motor, separate fromthe first motor, to actuate the second gas moving device. A first powersignal used to drive the first motor is approximately 180° out of phasewith a second power signal used to drive the second motor, and whereinfrequencies of the first and second power signals are dithered over a20% span at a rate of 900 Hz to reduce generated electromagneticinterference.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods.

In another aspect, an oxygen delivery device is disclosed. The oxygendelivery device includes an oxygen delivery module to produce at leastconcentrated oxygen, a gas moving device to deliver air to an oxygendelivery module, the gas moving device being driven by a motor toactuate the gas moving device, a purity sensor to determine oxygenpurity value produced by the oxygen delivery module, and a controller tocontrol operations of at least the oxygen delivery module and the gasmoving device, based at least in part on the determined oxygen purityvalue, to cause the purity level of the oxygen produced by the oxygendelivery module to be less than 90%.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods.

In yet another aspect, an oxygen delivery device is disclosed. Theoxygen delivery device includes an oxygen delivery module to produce atleast concentrated oxygen, a gas moving device to deliver air to theoxygen delivery module, the gas moving device being driven by a motor toactuate the gas moving device, a communication module to communicatewith a remote sensor configured to determine peripheral oxygensaturation of a patient, and a controller to control operations of atleast one of the oxygen delivery module and the gas moving device, basedat least in part on the determined peripheral oxygen saturation, toadjust the oxygen purity level of the oxygen produced by the oxygendelivery module to cause the peripheral oxygen saturation level of thepatient to converge to a pre-determined required peripheral saturationlevel.

Embodiments of the device may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods, including any one of thefollowing features.

The remote sensor may include a pulse oximeter to monitor the patient'soxygen saturation, the pulse oximeter being secured to skin of thepatient.

The pulse oximeter may be configured to determine the change in lightabsorbance by the patient's tissue.

The communication module may be configured to wirelessly communicatewith the remote sensor.

In an additional aspect, a method is disclosed. The method includesreceiving data representative of peripheral oxygen saturation of apatient, the data being communicated from a remote sensor configured todetermine the peripheral oxygen saturation of the patient, andcontrolling operations of at least one of an oxygen delivery module anda gas moving device of an oxygen delivery device, based at least in parton the data representative of the determined peripheral oxygensaturation of the patient, to adjust the oxygen purity level of theoxygen produced by the oxygen delivery module to cause the peripheraloxygen saturation level of the patient to converge to a pre-determinedrequired peripheral saturation level.

Embodiments of the method may include any of the features described inthe present disclosure, including any of the features described above inrelation to the devices, system, and methods.

Other and further objects, features, aspects, and advantages of thepresent disclosure will become better understood with the followingdetailed description of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects will now be described in detail with referenceto the following drawings.

FIG. 1A is a block diagram of an oxygen delivery device.

FIG. 1B is a schematic diagram of an oxygen delivery device thatincludes an example embodiment of an air separation device.

FIG. 2A is a cross-sectional diagram of an example rotary gas movingdevice.

FIG. 2B is a cross-sectional view of an example rotary compressor.

FIG. 3 is an exploded perspective view of an example rotary compressor.

FIG. 4A is an exploded perspective view of a two-compressorimplementation operated by a single motor for use with, for example, anoxygen delivery device.

FIG. 4B is a cross-sectional view of the implementation of FIG. 4A.

FIG. 5 is a flow chart of an example procedure for moving/directing gasin, for example, an oxygen delivery device.

FIG. 6 is a flow chart of an example procedure for moving/directing gas.

FIG. 7A is a perspective, cut-away view of an example oxygen deliverymodule (concentrator) that may be used with an oxygen delivery device.

FIG. 7B is a perspective, exploded view of the concentrator illustratedin FIG. 7A.

FIG. 8 is a flow chart of an example embodiment of a procedure tocontrol fluid flow into an oxygen delivery device.

FIG. 9 is a flow chart of an example process cycle for the concentratorillustrated in FIGS. 7A and 7B.

FIG. 10 is a block diagram of one or more sensors that may be used withan oxygen delivery device.

FIG. 11 is a flow chart of an example procedure to control oxygenationlevel of a patient.

FIG. 12 is a flow chart of an example procedure to enable continuousbreathing monitoring and control of oxygen delivery modes.

FIG. 13 is a flow chart of an example procedure to monitor and controlfilter performance.

FIG. 14 is a block diagram of at least some components that may becontrolled by a control unit of a portable oxygen delivery device.

FIG. 15 is a flow chart of an example procedure to control operations ofan oxygen delivery device based on measured oxygen purity and pressurevalues.

FIG. 16 is a flow chart of an example procedure to deliver oxygenpulses.

FIG. 17 is a flow chart of an example procedure to control operations ofan oxygen delivery device.

FIG. 18 is a flow chart of another example procedure to controloperation of an oxygen delivery device based, at least in part, on apatient's tidal volume, FiO2 value, as well as on other factors.

FIG. 19 is a schematic diagram of a conserving (or demand) device thatmay be incorporated into an oxygen delivery device to more efficientlyutilize the oxygen produced by an oxygen gas generator.

FIG. 20 is a flow chart of an example procedure to control oxygendelivery.

FIG. 21 is a schematic diagram of an oxygen delivery used with anebulizer.

FIG. 22 is a flow chart of an example procedure to implement remote setup.

FIG. 23 is a flow chart of an example procedure to deliver aerosolizedmedications.

FIG. 24 is a flow chart of an example procedure to deliver fluid vapor.

FIG. 25 is a flow chart of an example procedure to operate an oxygendelivery device.

FIG. 26 is a flow chart of an example procedure to operate an oxygendelivery device.

FIG. 27A is a diagram of an example embodiment of an O2 control mainflow.

FIG. 27B is a flow chart of an example procedure to control an oxygendelivery device.

FIG. 28 is a block diagram illustrating an example computer system.

FIG. 29 is a cross-sectional diagram of an example embodiment of a checkvalve and integrated filter assembly.

FIG. 30 is a schematic diagram illustrative of performance of an oxygendelivery device.

FIG. 31 is a flow chart of another example procedure to control anoxygen delivery device.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

Disclosed herein are systems, methods and devices, including variousimplementations and embodiments of oxygen delivery devices.

In some implementations, an oxygen delivery device is provided thatincludes an oxygen delivery module (e.g., a pressure swing adsorptionsystem, vacuum-pressure swing adsorption system, a vacuum swingadsorption system, a membrane seperator) to produce at leastconcentrated oxygen at a controllable purity level from ambient air, agas moving device (e.g., a compressor, a vacuum pump) to deliver theambient air to the oxygen delivery module), at least one controllablemotor to controllably drive the gas moving device, an energy source topower the at least one controllable motor, a pressure sensor todetermine a pressure level produced in the oxygen delivery device, and apurity sensor to determine oxygen purity value produced by the oxygendelivery module. The oxygen delivery device further includes acontroller to control, based on the determined oxygen purity value andthe pressure level, at least the gas moving device's operations and theoxygen delivery module's operations so as to cause the pressureresulting from the operation of the gas moving device to besubstantially at a pre-determined pressure value and to cause the puritylevel of the oxygen produced by the oxygen delivery module to besubstantially at a pre-determined purity value.

Also disclosed is an oxygen delivery device that includes an oxygendelivery module to produce at least concentrated oxygen, and acontroller configured to control the oxygen delivery module to cause theoxygen delivery module to deliver oxygen to a patient based on apatient's tidal volume data representative of the normal volume of airdisplaced between inspiration and expiration by the patient, and furtherbased on a fraction of inspired oxygen (FiO2) value required for thepatient.

Further disclosed is an oxygen delivery device that includes an oxygendelivery module, at least one sensor to detect patient breathing, and acontroller configured to control the oxygen delivery module to cause theoxygen delivery module to deliver oxygen to the patient based on datafrom the at least one sensor such that in response to a determination,based on data from the at least one sensor, that no breathing isdetected for a first period of time, the controller causes the oxygendelivery module to deliver oxygen to the patient in continuous flowmode, and in response to a subsequent determination, based on data fromthe at least one sensor, that breathing is detected for a second periodof time, the controller causes the oxygen delivery module to deliveroxygen to the patient in a pulse flow mode.

Also disclosed is an oxygen delivery device that includes an oxygendelivery module, one or more sensors to determine data representative ofone or more of environmental conditions, operating conditions of theoxygen delivery device, and patient's characteristics, a controller tocontrol, based at least in part on the determined data, at least theoxygen delivery module's operations, and a display module to presentinformation based, at least in part, on the data representative of thecharacteristics of the patient.

In some implementations, an oxygen delivery device is provided thatincludes an oxygen delivery module configured to deliver a pulseincluding greater than 100 mL of concentrated oxygen, and a controllerconfigured to control the oxygen delivery module to cause the oxygendelivery module to deliver the pulse including greater than the 100 mLof the concentrated oxygen within approximately first 60% of a patient'sinspiratory period.

Further disclosed is an oxygen delivery device that includes an oxygendelivery module to provide at least concentrated oxygen, a piezoelectricvalve coupled to an output of the oxygen delivery module to receive theproduced concentrated oxygen, a driver to electrically actuate thepiezoelectric valve, and a controller to control the driver to causecontrollable actuation of the piezoelectric valve by the driver so as tocause controllable opening of the valve to enable flow of oxygendelivered by the oxygen delivery module to be directed for inhalation bya patient via the piezoelectric valve.

Further disclosed is an oxygen delivery device that includes an oxygendelivery module to produce at least concentrated oxygen, and a gasmoving device to deliver air to the oxygen delivery module. The gasmoving device includes at least one piston rotatable inside a firstchamber defined in a housing, the rotational movement of the at leastone piston inside the first chamber resulting in varying pressuregenerated in a first portion of the first chamber, and a vane memberrigidly coupled to the at least one piston, the vane member beingconfigured to move inside a vane chamber defined in the housing. The atleast one piston and the vane rigidly coupled to the at least one pistondefining the first portion of the first chamber and a second portion ofthe first chamber.

These and other embodiments of oxygen delivery devices are discussed ingreater detail below.

I. Portable Oxygen Concentration System

With reference to FIG. 1A, a schematic diagram of a portable oxygenconcentration system (also referred to herein as an oxygen deliverydevice), indicated generally by the reference numeral 100, andimplemented in accordance with embodiments of the present disclosure, isshown. The oxygen delivery device 100 includes an air separation devicesuch as an oxygen gas generator 102 that separates concentrated oxygengas from air (ambient air), an energy source 104 such as rechargeablebattery, battery pack, fuel cell, and/or a power transformer module(e.g., AC/DC or DC/DC converters) that powers at least a portion of theoxygen gas generator 102, and one or more output sensors 106 used tosense one or more conditions of the user 108, of the environment, etc.,to determine the oxygen output needed by the user or required from thesystem 100. As depicted in FIG. 1, the device 100 also includes acontrol unit 110 (also referred to herein as a controller) coupled tothe output sensor 106, the air separation device 102, and the energysource 104 to control the operation of the air separation device 102 inresponse to the one or more conditions sensed by the one or more outputsensors 106.

In some embodiments, the device 100 may not include the one or moreoutput sensors 106 coupled to the control unit 110. In such embodiments,conditions of the device 100, such as flow rate, oxygen concentrationlevel, etc., may be constant for the system or may be controllable. Forexample, the system 100 may include a user interface (such as the userinterface 111 depicted in FIG. 14) that enables a user, provider,doctor, etc., to enter information, e.g., prescription oxygen level,flow rate, etc., to control the oxygen output of the system 100.

Each element of the system 100 will now be described in more detail. Afurther description of other implementation of oxygen delivery device isprovided, for example, in U.S. Pat. No. 6,691,702, entitled “Portableoxygen concentration system and method of using the same,” the contentof which is hereby incorporated by reference in its entirety.

A. Air Separation Device

With reference to FIG. 1B, a schematic diagram of a portable oxygenconcentration system 100 (an “oxygen delivery device”) is shown. In someembodiments, the air separation device is an oxygen generator 102generally including a gas moving device, such as a compressor 112, andan oxygen delivery module 114 (also referred to as an oxygenconcentrator, or OC) to provide at least concentrated oxygen, and may,in some embodiments, provide other types of concentrated gas). In someimplementations, the oxygen delivery module may include one or more of,for example, a pressure swing adsorption system, a vacuum-pressure swingadsorption system, a liquid oxygen storage system, and/or a highpressure gaseous oxygen system. The gas moving device and oxygendelivery module may be integral.

In some embodiments, the oxygen generator 102 may also include one ormore of the elements described below and shown within the segmentedboundary line in FIG. 1B. Ambient air may be drawn through an inletmuffler 116 by the gas moving device (e.g., the compressor) 112. Thecompressor 112 may be driven by one or more DC motors 118 (M) that runoff of DC electrical current supplied, for example, by the rechargeablebattery 104 (RB). The motor 118 may also, in some embodiments, drive thecooling fan part of the heat exchanger 120. A variable-speed controller(VSC) or compressor motor speed controller 119 may be integral with orseparate from the control unit 110 (CU) and may be coupled to the motor118 to facilitate conserving electricity consumption. The compressor 112delivers the air under pressure to the oxygen delivery module 114 thatproduces the at least concentrated oxygen.

In some embodiments, at maximum speed, air may be delivered to theoxygen delivery module 114 at 7.3 psig nominal and may range from 5.3 to12.1 psig. At maximum speed, the flow rate of feed may be a minimum of23.8 SLPM at inlet conditions of 14.696 psi absolute, 70 degrees F., 50%relative humidity.

In some implementations, a heat exchanger 120 may be located between thecompressor 112 and the oxygen delivery module 114 to cool or heat theair to a desired temperature before entering the concentrator 114. Afilter (not shown) may be located between the compressor 112 and theoxygen delivery module 114 to remove any impurities from the supply air,and a pressure transducer 122 may be located between the compressor 112and the, oxygen delivery module 114 to get a pressure reading of the airflow entering the oxygen delivery module 114.

The oxygen delivery module 114 separates oxygen gas from air foreventual delivery to the user 108 via, for example, a supply line 121.One or more of the following components may be located along the supplyline 121 between the concentrator 114 and the user 108: a pressuresensor 123, a temperature sensor 125, a pump 127, a low-pressurereservoir 129, a supply valve 160, a flow and purity sensor 131, and aconservation device 190. As used herein, supply line 121 may refer tothe tubing, connectors, etc., used to connect the components in theline. The pump 127 may be driven by the motor 118, or by another motor.The oxygen may be stored in the low-pressure reservoir 129 and deliveredtherefrom via the supply line 121 to the user 108. The supply valve 160may be used to control the delivery of oxygen gas from the low-pressurereservoir 129 to the user 108 at atmospheric pressure.

Exhaust gas may also be dispelled from the oxygen delivery module 114.In some embodiments, another gas moving device 124 (e.g., such as avacuum generator), which may also be driven by the motor 118 and may beintegral with the compressor 112, draws exhaust gas from the oxygendelivery module 114 to improve the recovery and productivity of theoxygen delivery module 114. The exhaust gas may exit the system 100through an exhaust muffler 126. A pressure transducer 128 may be locatedbetween the concentrator 114 and the vacuum generator 124 to get apressure reading of the exhaust flow from the oxygen delivery module114. At maximum rated speed and a flow rate of 20.8 SLPM, the pressureat the vacuum side is, in some embodiments, −5.9 psig nominal and mayrange from −8.8 to −4.4 psig.

It is to be noted that in some embodiments, gas moving devices (e.g., acompressor and/or a vacuum pump) may be provided where the compressorand vacuum pump are included in a single casing driven by a singlemotor. However, in some embodiments, the compressor and vacuum pump maybe separate elements. For instance, a separate variable speed compressorand a separate variable speed vacuum pump may be included where thecompressor and vacuum pump are driven by separate motors and are thuscapable of running independently from one another. In such aconfiguration, a VPSA system may be run at a multiplicity of settingsbased on a pressure and vacuum set point that has been optimizedindividually or based on a given pressure to vacuum and/or flow topressure ratio. Optimization of the pressure and vacuum set pointsrefers to a condition or conditions where the power required to run thesystem is relatively low for a specified oxygen flow and oxygen puritythan a comparable system that has not been so optimized.

Thus, in some embodiments, an oxygen delivery device may be providedthat includes an oxygen delivery module to produce at least concentratedoxygen, a first gas moving device (e.g., a compressor) to deliver air tothe oxygen delivery module, with the first gas moving device beingdriven by a first motor to actuate the gas moving device to run atvariable speeds, and a second gas moving device (e.g., a vacuum pump) todraw exhaust gas from the oxygen delivery module, with the second gasmoving device being driven by a second motor, separate from the firstmotor, to actuate the second gas moving device to run at variablespeeds.

By including an independent compressor and vacuum pump the system is notlimited to operation at a fixed flow ratio, and may, therefore, be runat different operating points that may be optimized so as to account fora variety of inputs such as oxygen flow, a given ambient temperature oratmospheric pressure, required output purity, and the like. Furtheroptimization may be achieved by combining the control of the compressorand/or vacuum pump in combination with one or more sensors fordetermining the purity of the flow. In such a manner, a purity feedbackloop, for example, may be established so as to control the operation ofthe system at the lowest acceptable level of purity that istherapeutically appropriate and thereby reduce the power consumed. Sucha range would be 85-90% oxygen purity, but could extend as low as 40%oxygen purity. As described herein, generally any suitable motor may beused to drive a compressor and/or vacuum pump described herein. In someembodiments, the motor may be a variable speed motor.

Thus, in such embodiments, an oxygen delivery device may be providedthat further includes at least one sensor to determine datarepresentative of one or more of environmental conditions, operatingconditions of the oxygen delivery device, and patient's therapeuticconditions, and one or more controllers to control the speeds of thefirst gas moving device and the second gas moving by controllingoperations of at least the first motor and the separate second motorbased on the determined data. In some embodiments, each motor drivingits respective gas moving device may be controlled by a separatecontroller, and in some embodiments a single controller may be used tocontrol both motors. The determined data representative of the one ormore of the environmental conditions, the operating conditions of theoxygen delivery device, and the patient's therapeutic conditions mayinclude data representative of one or more of, for example, oxygen flow,ambient pressure, ambient temperature, and/or required oxygen purity.

In some embodiments, an oxygen delivery device may include separatemotors for two different gas moving devices that are controlled using anoxygen purity feedback mechanism. Thus, in such embodiments, an oxygendelivery device may be provided that includes an oxygen delivery module(e.g., a PSA, VPSA) to produce at least concentrated oxygen, a first gasmoving device to deliver air to an oxygen delivery module, with thefirst gas moving device being driven by a first motor to actuate the gasmoving device to run at variable speeds, and a second gas moving deviceto draw exhaust gas from the oxygen delivery module, the second gasmoving device being driven by a second motor, separate from the firstmotor, to actuate the second gas moving device to run at variablespeeds. Such an oxygen delivery device also includes a purity sensor todetermine oxygen purity value produced by the oxygen delivery module,and a controller to control speeds of the first and second gas movingdevices by controlling operations of at least the first motor and theseparate second motor based, at least in part, on the determined oxygenpurity value, to cause the purity level of the oxygen produced by theoxygen delivery module to be substantially at a pre-determined purityvalue. In some embodiments, the pre-determined purity value may be theminimum acceptable oxygen purity level to enable energy consumption ofthe system to be reduced, such a pre-determined purity value having avalue of between approximately 82% and approximately 93% of oxygen.

The inclusion of separate compressor and vacuum pump motors could causean increase in the noise of the system and/or may cause an increase inthe mechanical vibrations and stress of the oxygen delivery device.Noise resulting from use of a separate compressor and vacuum pump may bereduced in part by configuring the motors and/or control thereof foractive EMI cancellation. For instance, the PWM signal used to drive thetwo motors may be configured so as to be 180° (or approximately 180°)out of phase with one another, and to have their frequencies be ditheredover a 20% span, such as at a rate of 900 Hz, thus reducing the noise ofthe system overall. For example, by controlling the currents drivingeach motor so as to be out of phase with one another, the ripple noiseon the DC bus may be cancelled and EMI reduced. Further noise reductionmay be achieved by dithering the frequency of the current which reducesthe radiated EMI. Accordingly, in some implementations, an oxygendelivery device may include an oxygen delivery module to produce atleast concentrated oxygen, a first gas moving device to deliver air tothe oxygen delivery module, with the first gas moving device beingdriven by a first motor to actuate the first gas moving device. Such anoxygen delivery device also includes a second gas moving device to drawexhaust gas from the oxygen delivery module, with the second gas movingdevice being driven by a second motor, separate from the first motor, toactuate the second gas moving device. In such implementations, a firstpower signal used to drive the first motor is approximately 180° out ofphase with a second power signal used to drive the second motor, andfrequencies of the first and second power signals are dithered over a20% span at a rate of 900 Hz to reduce generated electromagneticinterference.

In some embodiments, one or more stepper motors may be provided to drivethe oxygen delivery device's oxygen delivery module. For instance, amodulated stepper driver may be included where the controller produces amodulating signal that is injected into a full-step stepper motor drivesignal. For example, the controller may be configured (by appropriateprogramming of a programmable processor-based controller) to modulatethe slew rate of the full-step current waveform that is driven into thestepper motor coils. As a result, the vibration and structural noiseemanating from the stepper motor may be reduced without a loss inefficiency or the need for extraneous sound suppression methods.Accordingly, in such embodiments, an oxygen delivery device may beprovided that includes an oxygen delivery module to produce at leastconcentrated oxygen, a gas moving device to deliver the ambient air tothe oxygen delivery module, a stepper motor comprising one or moreelectromagnetic coils arranged around a gear element, with the steppermotor being configured to drive at least the oxygen delivery module.Such a device (also includes a controller configured to modulate thedriving signals used to energize the one or more electromagnetic coilsto achieve a specified slew rate so as to reduce the vibration andstructural noise emanating from the stepper motor without loss ofefficiency.

1. Compressor/Variable Speed Controller

Example of compressor technologies that may be used for gas movingdevices (e.g., the compressor 112 and vacuum generator 124 depicted inFIG. 1B) include, but not by way of limitation, rotary vane, linearpiston with wrist pin, linear piston without wrist pin, nutating disc,scroll, rolling piston, a rotatable piston (for use in implementationsof rotary gas moving device, which will be described in greater detailsbelow), diaphragm pumps, and acoustic. In some embodiments, thecompressor 112 and vacuum generator 124 are integrated with the motor118 and are oil-less, thus preventing the possibility of oil or greasefrom entering the air flow path.

The compressor 112 includes, in some embodiments, a 3:1 speed ratio,with a low speed of at least 1,000 rpm and a 15,000 hour operating lifewhen run at full speed. Operating temperature surrounding thecompressor/motor system may be, in some embodiments, 32 to 122 degreesF. Storage temperature may be −4 to 140 degree F. Relative humidity maybe 5 to 95% RH noncondensing. Voltage for the compressor 112 may be 12 VDC or 24V DC and the electrical power requirements may be less than 100W at full speed and rated flow/nominal pressure and less than 40 W at ⅓speed and ⅓ flow at rated pressure. A shaft mounted fan or blower may beincorporated with the compressor 112 for compressor cooling and possiblecomplete system cooling. In some embodiments, the maximum sound pressurelevel of the compressor 112 may be 46 dBA at a maximum rated speed andflow/pressure and 36 dBA at ⅓ rated speed. In some embodiments, thecompressor 112 weighs less than 3.5 pounds.

In some embodiments, the compressor 112 is configured to run at avariety of speeds, provide the required vacuum/pressure levels and flowrates, emit little noise and vibration, emit little heat, be small, notbe heavy, and consume little power.

The variable-speed controller 119 is important for reducing the powerconsumption requirements of the compressor 112 on the energy source 104.With a variable-speed controller, the speed of the compressor 112 may bevaried with the activity level of the user, metabolic condition of theuser, environmental conditions, or other condition indicative of theoxygen needs of the user as determined through the one or more outputsensors 106.

For example, the variable-speed controller may decrease the speed of themotor 118 when it is determined that the oxygen requirements of the user108 are relatively low, e.g., when the user is sitting, sleeping, atlower elevations, etc., and may increase the speed of the motor when itis determined that the oxygen requirements of the user 108 arerelatively high or higher, e.g., when the user stands, when the user isactive, when the user is at higher elevations, etc. This helps toconserve the life of the energy source 104, reduce the weight and sizeof the battery 104, and reduce the compressor wear rate, thus improvingits reliability.

Thus, in some embodiments, a variable-speed controller, such as thecontroller 119 depicted in FIG. 1B, to regulate the compressor speed tooperate the compressor only at the speed and power needed to deliveroxygen at the user's prescribed flow rate is provided. Such a variablespeed controller may thus be configured to regulate the speed of thecompressor (or other gas moving devices) based, at least in part, ondata determined by one or more sensors (i.e., through measurements)representative of one or more of environmental conditions (e.g., ambientpressure, ambient temperature), operating conditions of the oxygendelivery device (e.g., power level of the power source, existence offaults or malfunctions, etc.), and/or therapeutic conditions of the user(patient) using the oxygen delivery device (e.g., patient's breathingrate). Additional details regarding variable-speed controllers areprovided in U.S. Pat. Nos. 5,593,478 and 5,730,778, the contents of allof which are hereby incorporated by reference in their entireties asthough set forth in full.

The variable-speed controller 119 described herein allows the compressor112 to operate at a low average rate, where typically the average rateor speed will be between full speed and ⅙ full speed of the compressor112 (or some other gas moving device), resulting in an increase inbattery life, decrease in battery size and weight, and decrease incompressor noise and emitted heat.

Additionally, to facilitate controlling operations of the gas movingdevice (such as the compressor), a rotary valve is included with theoxygen delivery module (the rotary valve regulates the air flow enteringthe oxygen delivery module, and selectively transfers fluids into theoxygen delivery module) may be an indexed valve to enable determinationof operating state of the oxygen delivery module. For instance, thevalve assembly may include an index mark so that the valve position aswell as the number of valve rotations may be tracked. For example, therotary valve may include an indicator that indicates a rotary position.The indicator may be aligned with features on the face of the valve. Asthe indexing indicator passes a switch, a signal from the switch iscommunicated to the controller. In one embodiment, the switch may be anoptical switch (see, for example, the switch 1810 shown in FIG. 30) andthe indexing indicator may be an interrupt flag, such as for atransmissive type switch, or a contrasting color/stripe, such as for areflective type switch. In some embodiments, the switch may bemechanically activated and the indexing feature may be any suitablefeature sufficient to activate the switch by mechanical actuation of theswitch by the indexing indicator.

Accordingly, in some implementations, an oxygen delivery module, of anoxygen delivery device, may include one or more adsorbent bedsconfigured to selectively adsorb corresponding materials from fluiddirected through the one or more adsorbent beds, and a rotary valve forselectively transferring the fluid through the one or more adsorbentbeds, with the rotary valve including an index indicator detectable by asensor. The oxygen delivery device also includes one or more sensors todetect the indexing indicator on the rotary valve. In suchimplementations, a controller of the oxygen delivery device isconfigured to determine from information relating to the indexingindicator detected by the one or more sensors at least one of, forexample, rotational position of rotary valve, and/or number of rotationcycles completed by the rotary valve during a pre-determined period oftime. Such a controller may further be configured to cause actuation ofthe rotary valve, based on the rotational position of the rotary valvedetermined from the information relating to the detected indexingindicator, to rotate the rotary valve to a position where passagesbetween ambient air and the one or more adsorbent beds are closed so asto prevent atmospheric moisture from reaching the one or more adsorbentbeds.

As will be described in greater details below, in some implementations,the rotary valve may include a rotary valve shoe and a valve port platehaving respective engaged surfaces, with the rotary valve shoe beingrotatable to provide valving action for selectively transferring fluidstherethrough, the rotary valve shoe including multiple passages allowingfluid to flow therethrough. The rotary device also includes a fluiddistribution manifold to distribute fluids between the adsorption bedsand the valve members, with fluid distribution manifold includingmultiple passages allowing fluid to'flow through them, and one or morepassages of at least one of the rotary valve shoe and the fluiddistribution manifold including purge passages.

The determination of valve rotations is useful in tracking the number ofcycles performed, which in turn may be used to determine actual usage ofthe device and wear on the valve assembly. Further, in circumstanceswhere the motor is a stepper motor, when a stop command is issued, thecontroller can command the stepper to stop the valve one or more stepsafter the index mark has been passed. Such a configuration enables thevalve position to be such that there is no open conduit between theadsorbent and the ambient air, thus further serving to prevent moisturefrom interacting with the sieve.

With reference to FIG. 6, a flow chart of an example embodiment of aprocedure 450 based on the use of an indexed rotary valve is shown. Theprocedure 450 includes detecting 460 an indexing indicator on a rotaryvalve for an oxygen delivery module using one or more sensors (e.g., anoptical switch to optically detect the indexing indicator when theindexing indicator passes by the optical switch, a mechanical switchconfigured to be mechanically activated upon mechanical actuation of theswitch by the indexing indicator). A determination is made 470, e.g., bya controller in communication with the one or more sensors, based oninformation relating to the indexing indicator detected by the one ormore sensors, of at least one of, for example, rotational position ofthe rotary valve, and/or number of rotation cycles completed by therotary valve during a pre-determined period of time. As noted, in someembodiments, the rotary valve may be actuated based on the rotationalposition of the rotary valve determined from the information relation tothe detected indexing indicator, to rotate the rotary valve to aposition where passages between ambient air and the one or moreadsorbent beds are closed.

2. Rotary Gas Moving Devices

In some embodiments, it may be desirable to have the compressor andvacuum pump provided as a single unit. Thus, in some implementations, aswing compressor may be provided where the compressor and vacuum pumpare provided as two opposed heads that are integrated into a singleunit. The unit may include two rotating heads, e.g., a pressure and avacuum pump head, that are offset from one another so as to be about180° out of phase. In this manner, vibration and structural noise mayalso be reduced without having to introduce extraneous sound suppressionmechanisms.

The swing compressor may include a piston that articulates within acompression chamber, forming a compressor head, and a second piston thatarticulates within a second compression chamber, forming a vacuum head.The two heads may be positioned to be about 180° opposed to one another.As the piston of the compressor head approaches top-dead center,pressure in a first compression chamber increases, and as a result, thetorque required to turn the shaft driving the piston increases. Due tothe configuration of the system, this pressure and torque may beperiodic, e.g., roughly sinusoidal. The piston of the vacuum headproduces comparable pressures and torques as it reaches top-dead center.By offsetting these loads by about 180 degrees the sinusoidal pressuresand torques can serve to cancel one another out. By doing so, the netforces resulting on the swing compressor assembly are minimized, whichin turn leads to less vibration and therefore less sound beinggenerated, consequently reducing the noise level. This also serves tolessen peak torques in the assembly, which in turn reduces peakelectrical currents drawn by the motor driving the compressor head andvacuum head assembly.

Thus, as described herein, in some implementations, an oxygen deliverydevice is provided that includes an oxygen delivery module to produce atleast concentrated oxygen, and a gas moving device to deliver air to theoxygen delivery module. The gas moving device (e.g., a compressor, avacuum pump) includes at least one piston rotatable inside a firstchamber defined in a housing, the rotational movement of the at leastone piston inside the first chamber resulting in varying pressuregenerated in a first portion of the first chamber. The gas moving devicealso includes a vane member rigidly coupled to the at least one piston,the vane member being configured to move inside a vane chamber definedin the housing. The piston and the vane rigidly coupled to the pistondefine the first portion of the first chamber and a second portion ofthe first chamber. Implementations of a gas moving device that includeat least one such rotating piston may also be referred to as rotary gasmoving device, e.g., rotary compressors. In some embodiments, oxygendelivery devices, implemented using, for example, rotary gas movingdevices, may have a weight of between 2-15 pounds.

With reference to FIG. 2A, a cross-sectional diagram of a rotary gasmoving device (e.g., a rotary compressor) 200 is shown. Detailsregarding some implementations of rotary (swing) gas moving devices areprovided, for example, in co-owned patent application Ser. No.12/879,998, entitled “Rotary Compressor and Method,” the content ofwhich is hereby incorporated by reference in its entirety. In someembodiments, the rotary gas moving device (rotary compressor) 200includes, in some implementations, a stator 202 that is associated witha bushing 203, a vane 204, and a piston 205. The piston 205 is rotatableinside a chamber 222 defined in a housing 220 of the compressor. Thepiston may be, in some embodiments, a cylinder rotatable inside thechamber 222 having curved (arched) walls. The rotational movement of thepiston 205 results in varying pressure generated in a first portion 224of the first chamber 222. In some embodiments, the varying pressure maybe represented as a first periodic function (e.g., a sinusoidal-basedfunction) of the pressure generated in the first portion of the firstchamber. The vane 204 is rigidly coupled to the piston 205 and isconfigured to move inside a vane chamber 208 defined in the housing 220.The structure including the vane 204 rigidly coupled to the piston 205defines the first portion 224 of the chamber 222, and a second chamber225 (which, in some embodiments, may be a suction chamber).

As further shown in FIG. 2A, the rotary compressor 200 also includes ashaft 206 having the bearing 261 associated therewith. As can be seen,in this embodiment, the stator 202 includes the inlet port 210. Further,an inner chamber 262 and a passage 263 in the piston 205 form anaccumulator volume. The accumulator volume may function in part toreduce inlet pulsation noise. For instance, as the piston moves past thesuction port 210 in the stator 202, the incoming flow is abruptlyslowed. This inlet flow stagnation can result in pressure waves that cantypically cause objectionable noise. This configuration of the pistonaccumulation volume and stator containing inlet port can reduce theabrupt slowing of the flow and thereby reduce objectionable noise. Theaccumulator volume can also be formed by modifying the stator 202 in theinlet area or by allowing fluid communication between the vane chamber208 and second (suction) chamber 225. It is to be noted that since thepiston is moving relative to the stator, the inlet port will beperiodically opened and closed, as will be described in greater detailbelow.

Operation of the rotary compressor of oxygen delivery device will beexplained with reference to FIG. 2B showing a front elevation view ofanother example embodiment of a rotary compressor (which may similar tothe example embodiment of a rotary compressor shown in FIG. 2A).

In FIG. 2B, the inlet or suction port 210 is visible in a suctionendplate 218 (also shown in FIG. 3, described below). The location of adischarge port (not shown) is indicated by a discharge dimple 211located in the suction plate 218. As noted, the shaft 206 has acylindrical shaft eccentric 207 the centerline of which is parallel tobut not concentric with the shaft 206 centerline. The shaft eccentric207 occupies the space within the piston interior diameter, and isrotatably mounted with the inside diameter of the piston 205 such thatthe centerline of the piston 205 is eccentric with respect to thecenterline of the stator bore chamber 220. The interface between theshaft eccentric 207 and the interior diameter of the piston 205 mayadditionally include one or more bearings, e.g., rolling elementbearings, plain bearings, journal bearings, and the like.

As the shaft 206 rotates, e.g., clockwise, the offset eccentric rotates,thus driving the piston around in a rotation that is approximatelyorbital. The eccentricity of the piston 205 is such that the pistonoutside diameter contacts, or nearly contacts, a small zone of thestator surface defining the bore 220. The vane 204 extends radially fromthe piston 205, and is slidably engaged between the two bushings 203.The bushings 203 are rotatably engaged in the in the bushing chambers213.

As the shaft 206 continues to rotate the piston 205 is driven along acircular or orbital path. Rotation of the piston 205 is limited by theengagement of the vane 204 with the bushings 203. Therefore, the motionof the piston 205 is nearly orbital.

The arrangement of the vane 204 and the eccentricity of the piston 205is such that the volume within the stator bore chamber 220 is dividedinto a suction chamber 225 and a compression chamber 224. As the shaft206 rotates, e.g., clockwise, fluid is passed through the inlet port210, e.g., via tubing connected to a fluid source, and into the suctionchamber 225 that is increasing in volume as the compression chamber 224decreases in volume. The increasing volume of the suction chamber 225causes fluid to be drawn into the suction chamber 225 via the suctionport 210. As the piston 205 moves in its orbital rotation, the suctionport 210 becomes progressively closed off by the piston 205, and thesuction volume will become a compression volume.

As the piston 205 continues in its rotation, the compression volume 224decreases. The decreasing volume of the compression chamber 224compresses the fluid in the compression chamber 224 until the pressurein the compression chamber is approximately the same pressure as thefluid downstream of a discharge port 219 (depicted in FIG. 3).

The implementation of the rotary compressor 200 may include a valvecovering the downstream end of the discharge port 219 in a manner thatthe general flow of fluid is only permitted out of the compressionchamber 224. For example, in some embodiments, when the pressure withinthe compression chamber is about equal to or greater than the pressuredownstream of the discharge valve, the valve is caused to open and thefluid is forced out of the compression chamber 224.

As the shaft 206 continues to rotate the volume of the compressionchamber 224 reaches a minimum and the volume in the suction chamber 225reaches a maximum. Additional rotation isolates the suction volume 225from the suction port 210. At this point the suction chamber 225 nolonger draws fluid, and as the piston 205 continue to rotate the chamber225 will decrease in volume. Accordingly, at the point that the chamberinto which fluid (liquid and/or gas) was drawn no longer functions todraw fluid, that chamber becomes a compression chamber, whereas thehitherto compression chamber 224 will start drawing fluid into itsvolume, and thus will become a suction chamber. This cycle repeats asthe shaft rotates, such that a continuous flow of compressed fluid isproduced. Hence, fluid is continuously drawn in on one side, compressedand discharged on the other side of the larger bore chamber 222 of thecompressor 200.

The vane chamber 208 located near the top of the compressor in the FIG.2A operates, in part, as a clearance for the vane 204 such that as thepiston 205 rotates, the vane is moved up and down in and out of the vanechamber 208 in a linear and/or rotational oscillation. An optional vanechamber vent 209 (shown in FIG. 2B) is located in the vane chamber 208.The vane chamber vent 209 may be included so as to control the fluidpressure within the vane chamber. The vent 209 may be controlled by anexternal or internal source. For example, in certain instances, apressure source may be provided where the pressure source is in fluidcommunication with the vane chamber portion, e.g., through a controlledvane. Accordingly, a control mechanism may also be provided to controlthe fluid pressure in the vane chamber. In some implementations, thecontrol mechanism may control one or more of the valve and/or a pressuresource. The pressure source may be any suitable pressure source, and incertain instances the pressure source may include an ambient pressuresource, a pressure source that is above ambient pressure, or a pressuresource is below ambient pressure.

In some implementations, the compressor includes axially separatedsurfaces, and one or more endplates effectively sealing the firstchamber the rotatable piston includes a cylindrical piston with anexterior diameter, the cylindrical piston being operatively associatedwith a drive member disposed within the first chamber and rotatabletherein, and further being offset with respect to a centerline of thefirst chamber portion such that the exterior diameter of the piston isin close proximity to bounds of the first chamber portion during orbitof the piston, to divide the first chamber into a suction chamberportion and a compression chamber portion. Examples of suchimplementations are depicted in FIG. 3, showing an exploded perspectiveview of an example rotary compressor.

As noted, and as also depicted in FIG. 3, the rotary compressor 200includes several inter-related parts. For example, the compressorincludes the housing which may be formed as the stator 202 and mayinclude two endplates, namely, a discharge end plate 217 and a suctionend plate 218. As depicted, the discharge end plate 217 includes adischarge port 219, and the suction endplate 218 includes the suctionport 210. It is to be noted that although the discharge and suctionports are shown as being associated with respective endplates, in someembodiments, one or both ports may be associated with a single endplateor other parts of the compressor housing. Also, it is to be noted thatalthough the endplates are depicted as separate components from thehousing, an endplate can be an integral part of the housing.

With reference again to FIG. 2B, as noted, the cavity includes threesections or chambers. One chamber defines the vane chamber 208 (alsodiscussed in relation to FIG. 2A), in which the vane 204 resides andmoves. Another chamber is a bushing chamber 213 in which bushings 203reside. The chamber 222 comprises a large cylinder or bore chamber thatforms a suction and/or compression space volume in which the piston 205resides.

The vane 204 is an extended member, a portion of which is associatedwith the piston 205 and another portion of which extends into one orboth of the bushing chamber 213 and the vane chamber 208. In certaininstances, the vane is integrally formed with the piston and in otherinstances the vane is detachably attached to the piston.

The bushing chamber 213 may include one or more bushings and a vane. Thebushing chamber 213 of the stator 202 is formed by opposing curvedsurfaces which may interface with bushing bearings, which in turninterface with bushings 203. Consequently, the bushings 203 may includeboth a curved surface, configured to fit snugly within the curved recessof the bushing chamber of the stator 202 and/or bushing bearingspositioned therein, and a relatively flat surface, adapted to interfacewith a flat surface of the vane 204. The bushings 203 in conjunctionwith the vane 204 form a fluid seal that separates the suction and/orcompression portions (224 and 225, respectively, as depicted in FIG. 2A)defined in the bore chamber 222, from the vane chamber 208.

As noted, the piston 205 may be, in some implementation, a cylindricalmember comprising both an exterior portion having an exterior diameterand an interior portion having an interior diameter. The exteriorportion diameter is less than that of the large bore diameter and thusthe piston 205 does not occupy the entire space of the large borechamber 220, but rather moves about in an orbital motion therein. Theinterior diameter portion forms an orifice within which the shaft 206and a shaft eccentric 207 are positioned. The exterior portion of thepiston 205 includes a cut out portion, e.g., a vane cleft, which isconfigured for receiving a distal portion of the vane 204. The vane 204is rigidly coupled (affixed) to the piston 205 such that relative motionbetween the vane 204 and piston 205 generally does not occur.Alternatively, the vane 204 and piston 205 can be a single component.The vane 204 interacts with the piston 205 and the bushings 203 so as todefine two distinct sub-chambers within the large bore chamber 222,namely, the first chamber portion 224, and the second chamber portion225.

The piston 205 may be offset from a centerline of the large bore suchthat as the piston orbits within the bore the outer diameter portion ofthe piston approximates the exterior surface of the stator 202. In someembodiments, the outer portion may contact the exterior surface definingthe stator bore chamber, in other instances there will be a smallclearance there between. In instances where there is a small clearance,this clearance may range from about 1 micron up to, and including, about50 microns. Additionally, where there is an axial clearance betweenaxial surfaces, such as between the piston and the endplates, the axialclearance may range from about 1 to about 100 microns. In someembodiments, the compressor may have a compression ratio of betweenabout 1 and about 5 (for example, between about 2 or 2.5 and 4,including about 3 and about 3.15).

In some embodiments, the oxygen delivery device may further include atleast one additional gas moving device, with each of the additional gasmoving device including a corresponding additional piston rotatinginside a corresponding bore chamber defined in the housing, therotational movement of the corresponding additional piston inside thecorresponding bore chamber results in corresponding pressure representedas a corresponding additional periodic function created in acorresponding portion of the corresponding bore chamber, and acorresponding additional vane member coupled to the correspondingadditional piston, the corresponding additional vane being configured tomove inside a corresponding additional vane chamber defined in thehousing.

For example, in some embodiments, the oxygen delivery device may includetwo gas moving devices, e.g., two compressors. Thus, in suchembodiments, a first gas moving device may include a first pistonrotating inside a first chamber (e.g., a bore chamber) of the first gasmoving device) to facilitate compression operations, and a second gasmoving device includes a second, separate piston rotating inside asecond chamber (another bore chamber) defined in the housing tofacilitate vacuum pump operations.

Particularly, with reference to FIG. 4A, an exploded perspective view ofa two compressor implementation 300 operated by a single motor for usewith, for example, an oxygen delivery device is shown. Theimplementation 300 includes compressors 300A and 300B that are driven bya single motor 350. As can be seen with respect to FIG. 4A, the firstcompressor 300A includes a housing 302A, which is positioned between twoendplates 318A and 317. The second compressor 300B includes a housing302B, which is positioned between two endplates 318B and 317. Asdepicted, both compressors 300 A and B share the common endplate 317.However, in some embodiments, each compressor can each have its own,non-shared endplates. Also included are mufflers 321A and 321B. Inimplementations of two compressors driven by a single motor, as shown inthe cross-sectional view of FIG. 4B, one compressor may act to increasepressure above ambient pressure, and one compressor may act to reducepressure below ambient pressure. In some embodiments, gas may leak intoan endplate chamber, e.g., endplate chamber 319. Gas that leaks into theendplate chamber from the pressure unit may be relatively hot and at arelatively high pressure. Such gas will tend to be drawn from one unitinto another, such as into the vacuum unit, thus reducing efficiency. Avent hole 325 (shown in FIG. 4B), therefore, may be positioned in theshared endplate and used to keep the endplate chamber at an optimalpressure. This optimal pressure may be ambient pressure or some otherpressure and/or may be from another source. This can prevent sharedfluid exchange between the compressors and/or can reduce the effects ofthe pressure of one compressor from having deleterious effects on theother compressor.

It is to be noted that other types of gas moving devices may be used inaddition to or in place of the compressors 300A and 300B depicted inFIGS. 4A and 4B, and also that additional, gas moving devices may beused in a multi-gas moving device configuration. For example, in someembodiments, three, four, or more gas moving devices may be used, ofwhich one, some, or all may be driven by a single rotary power source.

As noted, in some embodiments, the operation of rotary pistons such asthose described herein may be implemented so as to reduce overallmechanical vibrations, reduce structural, stress, and/or reduce noiseproduce through operations of the gas moving devices. For example,mechanical vibrations, stress and/or noise can be reduced by havingrotary pistons (in implementations that employ multiple piston) have aphase offset from one another. Thus, in some implementations, forcesresulting from the rotational movement of a first piston in a firstchamber may destructively interfere with forces resulting from therotational movement of a second piston in a second chamber such that netforces created in the oxygen delivery device are reduced.

Thus, in embodiments such as those depicted in FIGS. 4A and 4B, thepistons could be rotating so that pressure (e.g., compression pressure)created in a first chamber where a first piston rotates (such pressurebeing represented as a periodic function) is approximately 180° out ofphase with pressure (e.g., compression pressure) created in a secondchamber where a second piston rotates (with the pressure in the secondchamber also represented as a periodic, for example, a sinusoidal,function). In some embodiments, the relative radial position of a firstpiston in a first chamber (where the first piston rotates), which may berepresented as a first periodic function, and the relative radialposition of a second piston in a second chamber (where the second pistonrotates), which may be represented as a second periodic function, areconfigured to be out of phase in relation to each other. That is, insome embodiments, the relative radial position of the two pistons aremade to be offset from each other (e.g., by about 180°) so that pressurebuild up in the chambers, and thus mechanical vibrations and noise, candestructively interfere with each other to reduce overall vibrations andnoise.

With reference to FIG. 5, a flow chart of an example embodiment of aprocedure 400 for moving/directing gas in, for example, an oxygendelivery device is shown. The procedure 400 includes supplying air 410to a gas moving device configured to deliver compressed air to an oxygendelivery module of an oxygen delivery device. At least one pistonrotatable inside a first chamber defined in the housing of the gasmoving device is actuated 420, with the rotational movement of the atleast one piston inside the first chamber resulting in varying pressure(which may be represented as a periodic function) generated in a firstportion of the first chamber. The at least one rotatable piston isrigidly coupled to a vane member configured to move inside a vanechamber defined in the housing, with the piston and the vane rigidlycoupled to it defining the first portion of the first chamber and asecond portion of the first chamber. Pressured air from the firstchamber, generated through the rotation of the at least one piston, isdirected 430 to the oxygen delivery module.

In some embodiments, actuation of the at least one piston may includeactuating a first piston rotatable inside a first chamber configured tooperate as a compressor to draw ambient air into the oxygen deliverymodule, with the rotational movement of the at least one piston insidethe first chamber resulting in compressor pressure created in the firstchamber that is represented as a first periodic function, and actuatinga second piston inside a second chamber of the housing, with the secondchamber configured to operate as a vacuum pump to draw exhaust gas fromthe oxygen delivery module. The rotational movement of the second pistoninside the second chamber results in vacuum pump pressure created in thesecond chamber that is represented as a second periodic function. Thefirst periodic function representative of the compressor pressure insidethe first chamber may be approximately 180° (or some other offset) outof phase relative to the second periodic function representative of thevacuum pump pressure created inside the second chamber such that forcesresulting from the rotational movement of the first piston in the firstchamber destructively interfere with forces resulting from therotational movement of the second piston in the second chamber.

3. Concentrator

With reference again to FIG. 1B, in some embodiments, the oxygendelivery module (also referred to herein as “concentrator”) 114 is anAdvanced Technology Fractionator (ATF) that may be used for medical andindustrial applications. The ATF may implement a pressure swingadsorption (PSA) process, a vacuum pressure swing adsorption (VPSA)process, a rapid PSA process, a very rapid PSA process, or otherprocesses. If a PSA process is implemented, the concentrator may includea rotating valve or a non-rotating valve mechanism to control air flowthrough multiple sieve beds. Examples of ATF concentrators are shown anddescribed in U.S. Pat. Nos. 5,268,021, 5,366,541, Re. 35,099, which arehereby incorporated by reference in their entireties as though set forthin full.

Although an ATF concentrator 114 is used in the implementationsdescribed herein, other types of concentrators or air-separation devicesmay be used such as, but not by way of limitation, membrane separationtypes and electrochemical cells (hot or cold). Use of other types ofconcentrators or air-separation devices may require modifications ofsome aspects described herein. For example, if the air-separation deviceis a membrane separation type, pumps other than a compressor may be usedto move air through the system.

The ATF's used in the implementations described herein are significantlysmaller than prior art implementations. It is noted that reducing thesize of the ATF concentrator 114 not only makes the system 100 (depictedin FIGS. 1A and 1B) smaller and more portable, but also improved therecovery percentage, i.e., the percentage of oxygen gas in air that isrecovered or produced by the concentrator 114, as well as theproductivity (liters per minute/lb. of sieve material) of theconcentrator 114. Reducing the size of the ATF decreases the cycle timefor the device. As a result, productivity is increased.

Further, use of finer sieve materials also increases recovery rates andproductivity. The time constant to adsorb unwanted gases is smaller forfiner particles at least partly because the fluid path is shorter forthe gases than for larger particles. An example of a sieve material thatmay be used in an ATF concentrator, such as the concentrator 114, isdescribed in U.S. Pat. No. 5,413,625, which is incorporated by referencein its entirety as though set forth in full. In some embodiments, thesieve material may be a LithiumX Zeolite that allows for a high exchangeof Lithium ions. The bead size may, for example, be 0.2-0.6 mm. In someembodiments, the Zeolite may be in the form of a rigid structure such asan extruded monolith or in the form of rolled up paper. In suchembodiments, the Zeolite structure would allow for rapid pressurecycling of the material without introducing significant pressure dropbetween the feed and product streams.

The size of the concentrator 114 may vary with the flow rate desired.For example, the concentrator 114 may come in a 1.5 Liter per minute(LPM) size, a 2 LPM size, a 2.5 LPM size, a 3 LPM size, etc.

The oxygen gas generator 102 may also include an oxygen source inaddition to the concentrator 114 such as, but not by way of limitation,a high-pressure oxygen reservoir.

An ATF valve controller 133 (depicted schematically in FIG. 1B) may beintegral with or separate from the control unit 110 and may be coupledwith valve electronics in the concentrator 114 for controlling the valve(s) of the concentrator 114.

The concentrator may have one or more of the following energy savingmodes: a sleep mode, a conserving mode, and an active mode. Selection ofthese modes may be done manually by the user 108 or automatically basedon data determined using the one or more sensors 106 and control unit110.

With reference to FIGS. 7A and 7B, an example embodiment of aconcentrator 114 that may be used in the oxygen generator 102 will nowbe described in more detail. Although the concentrator 114 will bedescribed as separating oxygen from air, it should be noted that theconcentrator 114 may be used for other applications such as, but not byway of limitation, air separations for the production of nitrogen,hydrogen purification, water removal from air, and argon concentrationfrom air. As used herein, the term “fluids” includes both gases andliquids.

The concentrator 114 includes numerous improvements over previousconcentrators that result in increased recovery of the desired componentand increased system productivity. Improved recovery is important sinceit is a measure of the efficiency of the concentrator. As aconcentrator's recovery increases, the amount of feed gas required toproduce a given amount of product decreases. Thus, a concentrator withhigher recovery may require a smaller feed compressor (e.g., for oxygenconcentration from air) or may be able to more effectively utilize feedgas to recover valuable species (e.g., for hydrogen purification from areformate stream). Improved productivity is important since an increasein productivity relates directly to the size of the concentrator.Productivity is measured in units of product flow per mass or volume ofthe concentrator. Thus, a concentrator with higher productivity will besmaller and weigh less than a concentrator that is less productive,resulting in a more attractive product for many applications. Therefore,concentrator improvements in recovery, productivity, or both areadvantageous.

As shown in FIG. 7A, the concentrator 114 includes, in some embodiments,multiple (e.g., five) adsorption beds 500, each containing a bed ofadsorbent material which is selective for a particular molecular speciesof fluid or contaminant, two rotary valve assemblies 510, 511 forselectively transferring fluids through the adsorption beds 500, and anintegrated tube-assembly and manifolds 520/530/575.

The adsorption beds 500 are, in some implementations, straight,elongated, noncircular vessels. The beds may also have circular crosssections. The adsorption beds 500 are surrounded by the metal cover 530to provide structural support and to mitigate the detrimental effects ofwater influx that occur when adsorbents are exposed to ambient moisture.The adsorption bed vessels are capped by the manifolds 520 and 575.

Each adsorption bed 500 may include a product end 550 and a feed end560. The product ends 550 of the beds 500 communicate with productpassages (not shown in FIGS. 7A and 7B) of a product manifold 575 forcommunication with the rotary valve assembly 511. The feed ends 560 ofthe beds 500 communicate with incoming and outgoing gas passages (notshown) of the feed manifold 520 for communication with the rotary valveassembly 510.

The feed manifold 520 may also include an incoming feed passage thatcommunicates the rotary valve assembly 510 with a feed pressure line524, and a vacuum chamber that communicates the rotary valve assembly510 with a vacuum pressure line 522. A product delivery line,communicates with the low pressure reservoir 129. The vacuum pressureline may communicate directly or indirectly with the vacuum generator124 for drawing exhaust gas from the concentrator 114. Mounted on themanifold 520 is a compound gear 526 that includes a lower gear 527(e.g., a worm type gear) for engaging with a worm gear on the motorshaft, and an upper gear 228 (e.g., a spur type gear) for engaging withthe rotary valve.

In operation, air flows from the compressor 112 to the feed pressureline 524, and through the incoming feed passage of the feed manifold520. From there, air flows to the feed rotary valve assembly 510 whereit is distributed back through outgoing feed passages of the feedmanifold 520. From there, the feed air flows to the feed ends 560 of theadsorption beds 500.

The adsorption beds 500 include adsorbent media that is appropriate forthe species that will be adsorbed. For oxygen concentration, packedparticulate adsorbent material may be used that adsorbs, for example,nitrogen relative to oxygen in the feed air so that oxygen is producedas the non-adsorbed product gas. Thus, in some embodiments, an adsorbentsuch as a highly Lithium exchanged X-type Zeolite may be used. A layeredadsorbent bed that contains two or more distinct adsorbent materials mayalso be used. As an example, for oxygen concentration, a layer ofactivated alumina or silica gel used for water adsorption may be placednear the feed end 560 of the adsorbent beds 500 with a lithium exchangedX-type zeolite used as the majority of the bed toward the product end550 to adsorb nitrogen. The combination of materials, used correctly,may be more effective than a single type of adsorbent. In alternativeembodiments, the adsorbent may be a structured material and mayincorporate both the water adsorbing and nitrogen adsorbing materials.

The resulting product oxygen gas flows towards the products ends 550 ofthe adsorption beds 500, through the product manifold 575, product portplate 557, and to the product rotary valve 556. It then redirected bythe product rotary valve 556 and product port plate 557 into otherpassages of the product manifold 575 and directed via the outgoingproduct passage and into a low pressure reservoir 129. From the lowpressure reservoir 129, oxygen gas is supplied to the user (e.g., theuser 108 in FIG. 1A) through the supply line 121.

With reference to FIG. 7B, a diagram of an example embodiment of thefeed rotary valve assembly 510 is shown. The rotary valve assembly 510includes a feed rotary valve shoe or disk 512 and a feed valve portplate (or disk) 514. The feed rotary valve shoe 512 and feed valve portplate 514 both have, in some implementations, a circular shape, and maybe made from a durable material such as, for example ceramic orengineering thermoplastic, which can be ground to a highly polished flatfinish to enable the faces of the feed valve shoe 512 and feed valveport plate 514 to form a fluid-tight seal when pressed together.

The feed rotary valve shoe 512 and the product rotary valve shoe 556 mayhave a flat, bottom engagement surface and a smooth cylindricalsidewall. The feed valve shoe 512 and the product rotary valve shoe 556may have several symmetrical arcuate passages or channels cut into theengagement surface, all of which may have as their center the geometriccenter of the circular engagement surface. The passages or channelsinclude opposite high-pressure feed channels, equalization channels,opposite low-pressure exhaust passages, circular low-pressure exhaustgroove which communicates with exhaust passages, opposite productdelivery channels, opposite purge channels, a high-pressure central feedpassage, a first annular vent groove, and a second annular vent groove.

The feed valve port plate 514 and product valve port plate 557 generallyhave a flat engagement surface 515, configured to engage the flatengagement surface of the opposing rotary valve shoe, and a smoothdisc-shaped (cylindrical sidewall) body 516. An underside of the valveport plates 514 may be disposed on a manifold gasket (not shown). Thevalve port plates 514, 557 also includes multiple sets of generallysymmetric concentrically disposed ports or openings aligned withopenings in the manifold gasket to communicate the ports in the plates514, 557 s with the passages in the respective manifolds 520 and 575.The ports extend vertically through the valve port plate 514, 557 in adirection generally substantially perpendicular to the engagementsurface 515. In some embodiments, the ports may extend through the valveport plate 51, 5574 in an angular direction toward the engagementsurface 515. Generally, all of the ports of each concentric set have thesame configuration.

As noted, in some embodiments, the feed valve port plate 514 and theproduct valve port plate 557 may include multiple concentric sets ofports concentrically disposed at various radii from the geometric centerof the feed valve port plate 514 and product valve port plate 557. Forexample, in some implementations, one set of ports may be configured tocommunicate with the vacuum chamber of the manifold 520 and the exhaustgas grooves of the valve shoe 512. Another set of ports (which, in someembodiments, includes five round ports) corresponds to the outgoing feedports that are concentrically disposed at a second radius from thegeometric center of the valve port plate 514, and communicate withoutgoing feed passages of the manifold 520, the feed channels of thevalve shoe 512, and the vacuum ports via the exhaust passages of thevalve shoe 512. Another set of ports are incoming product ports thatcommunicate with the incoming product passages of the product manifold575, the equalization channels of the product valve shoe 556, the purgechannels of the product valve shoe 556, and the product deliverychannels.

Within the channels of the product valve shoe there may be passages thatallow for fluid communication between adsorption beds. This fluidcommunication may be for the purposes of purge, product delivery, orequalization. Said passages may pass substantially perpendicular to theface of the valve shoe or though the cylindrical sidewall so as to be influid communication with one or more channels.

A round central incoming feed port may also be included on the feed portplate 514 to communicate with the incoming feed passage of the feedmanifold 520 and the central feed passage of the feed rotary valve shoe512. Additional sets of ports on the feed port plate 514 of the rotaryvalve 510 may be included.

In the rotary valve assemblies 510 and 511 described above, a maximum of1 PSI pressure drop occurs through any port of the valve assembly 510when the system is producing 3 LPM of oxygen product. At lesser flows,the pressure drop is negligible.

In some embodiments, when in operation, a rotary valve such as therotary valve 510 depicted in FIGS. 7A and 7B may stop in a position thatcreates a continuous open passage allowing ambient air to come intocontact with adsorbent material in the adsorbent beds of an oxygendelivery module (e.g., an oxygen delivery module implemented as apressure swing adsorption, or PSA, a vacuum pressure swing adsorptionsystem, or VPSA, etc.) In such situations, the size of the diffusionpathway may not be sufficient to prevent atmospheric moisture fromcontaminating the adsorbent. Hence, in such circumstances, it may beuseful to control the stopping of the valve such that as the valve stopsthe position of the valve prevents such an open passage and thusatmospheric moisture cannot reach the adsorbent, for instance, when thePSA system is not operating. Therefore, a controller, such as thecontroller 119 depicted in FIG. 1B, may be configured to perform ashutdown sequence so as to control one or more rotary valves of thesystem such that when the valve shuts down inadvertent communicationwith a source of moist air can be avoided. In some implementations, oneor both of a rotary encoder or shaft position indicator, for example,may be included and positioned in proximity to the rotary valve or shaftand operatively coupled to the controller, which in turn can control thefunctioning of the rotary valve. Under these circumstances, the sieve inthe VPSA or PSA module may be isolated from ambient moisture, therebyincreasing module life.

Thus, in some embodiments, an oxygen delivery device may be providedthat includes an oxygen delivery module to produce at least concentratedoxygen. As noted, examples of such an oxygen delivery module include,for example, a pressure swing adsorption system (PSA), a vacuum-pressureswing adsorption system (VPSA), vacuum swing adsorption system (VSA),etc. The oxygen delivery module includes one or more adsorbent bedsconfigured to selectively adsorb corresponding materials from fluiddirected through the one or more adsorbent beds, a rotary valve forselectively transferring the fluid through the one or more adsorbentbeds, and one or more position sensors to determine a valuerepresentative of the rotational position of the rotary valve. Theoxygen delivery device may further include (in addition to the oxygendelivery module) a controller configured to, in response to terminationof operation of the oxygen delivery module, cause actuation of therotary valve (e.g., using a stepper motor, which may separate andindependent from other motors included with the device that drive otherunits/components of the device), based on the data determined by the oneor more position sensors, to rotate the rotary valve to a position wherepassages between ambient air and the one or more adsorbent beds areclosed so as to prevent atmospheric moisture from reaching the one ormore adsorbent beds.

With reference to FIG. 8, a flow chart of an example embodiment of aprocedure 600 to control fluid flow into an oxygen delivery device isshown. The procedure 600 includes determining 610 rotary position of arotary valve (such as, for example, the rotary valves 510, 511 shown inFIG. 7B) for an oxygen delivery module using one or more positionsensors, with the rotary valve being configured to selectively transferfluid through the one or more adsorbent beds that selectively adsorbcorresponding materials from the fluid. In response to termination ofoperation of the oxygen delivery module, the rotary valve iscontrollably actuated 620, based on the data determined by the one ormore position sensors, to rotate the rotary valve to a position wherepassages between ambient air and the one or more adsorbent beds areclosed so as to prevent atmospheric moisture from reaching the one ormore adsorbent beds. In some embodiments, the one or more positionsensors may include at least one of, for example, a rotary encoder,and/or a shaft position indicator, which may be placed proximate one ormore of, for example, the rotary valve, and/or a shaft coupled to therotary valve.

Operations of the oxygen delivery module will now be described. Withreference additionally to FIG. 9, showing a flow diagram of an exampleembodiments of a process 700 performed in the course of a singlepressure swing adsorption cycle of an oxygen delivery module, such asthe concentrator 114. During use, the rotary valve shoes 512, 556rotates with respect to the valve port plates 512, 557 so that the cycledescribed below is sequentially and continuously established for eachadsorption bed 500. The speed of rotation of the feed valve shoe 512 andproduct valve shoe 556 with respect to the feed port plate 514 andproduct port plate 557 may be varied alone, or in combination with avariable-speed compressor, in order to provide the optimal cycle timingand supply of ambient air for a given production of product. With eachrevolution of the valve shoes 512 and 556, the adsorption beds 500undergo two complete cycles. For each cycle, the stages/operationsinclude: 1) pre-pressurization 702, 2) adsorption 704, 3) firstequalization down 706, 4) second equalization down 708, 5) co-currentblowdown 710, 6) low-pressure venting 712, 7) counter-current purge andlow-pressure venting 714, 8) first equalization up 716, and 9) secondequalization up 718. The following description of the cycle is providedwith respect to one of the multiple adsorbent beds 500 of the oxygendelivery module. Additional details regarding this procedure, as well asconfigurations and implementations of oxygen delivery devices withrespect to which the process 700 is performed are provided, for example,in U.S. Pat. No. 6,691,702, entitled “Portable oxygen concentrationsystem and method of using the same,” the content of which is herebyincorporated by reference in its entirety.

During pre-pressurization 702, air flows from the compressor 112 to thefeed pressure line, through the incoming feed passage of the feedmanifold 520. From there, air flows through the central incoming feedport of the feed port plate 514, through the central feed passage andout the feed channels of the feed valve shoe 512, through the outgoingfeed ports, and through outgoing feed passages of the feed manifold 520.From there, the feed air flows to the feed ends 560 of the adsorptionbeds 500. Because the feed channel is advanced with respect to theproduct delivery channel (i.e., initially the feed channel is incommunication with outgoing feed port and the product delivery channelis blocked, and is not in communication with the incoming product port),the feed end 560 of the adsorption bed 500 is pressurized with feed gas,i.e., pressurized, prior to the commencement of product delivery. Inalternative embodiments, the product end 550 may be pre-pressurized withproduct gas, or the product end 550 may be pre-pressurized with productgas and the feed end 560 may be pre-pressurized with feed gas.

At the adsorption stage 704, because the product delivery channel is incommunication with the incoming product port, adsorption of Nitrogenoccurs in the bed 500 and the resulting product oxygen gas flows towardsthe product ends 550 of the adsorption beds 500, through the productlines, and through incoming product passages of the product manifold575. From there, oxygen gas flows through the incoming product port,into and out of the product delivery channel, through outgoing productport, through the outgoing product passage, and into the low pressureoxygen reservoir 129. From the low pressure oxygen reservoir 129, oxygengas is supplied to the user 108 through the supply line 121 (shown inFIG. 1B).

In the first equalization-down stage 706, the product end 550 of the bed500, which is at a high pressure, is equalized with the product end ofanother bed, which is at a low pressure, to bring the product end 550 ofthe bed 500 to a lower, intermediate pressure. The product ends 550communicate through the equalization channels of product valve 556,passages of product port plate 557 and passages of product manifold 575.During the stage 706 and the equalization stages 708, 716, and 718, moreparticularly described below, the adsorption beds 500 may be equalizedat either the feed end 560, the product end 550, or a combination of thefeed end 560 and the product end 550.

During the second equalization-down stage 708, the product end 550 ofthe bed 500, which is at an intermediate pressure, is equalized with theproduct end of another bed, which is at a lower pressure, to bring theproduct end 550 of the bed 500 further down to an even lower pressurethan in stage 706. Similar to the first equalization-down stage 706, theproduct ends 550 communicate through equalization channels of productvalve 556, passages of product port plate 557 and passages of productmanifold 575.

In the co-current blowdown (“CCB”) stage 710, oxygen enriched gasproduced from the product end 550 of the adsorption bed 500 is used topurge a second adsorption bed 500. Gas flows from the product side ofthe adsorption bed 500, through passages of product port plate 557 andpassages of product manifold 575. The gas further flows through purgechannels and purge passages, of the product valve shoe 556, through thepurge channel, through the incoming product port, through the incomingproduct passage, through the product line, and into the product end 550of adsorption bed 500 to serve as a purge stream. In alternativeembodiments, during stage 710 and the following stage 712, co-currentblowdown may be replaced with counter-current blowdown.

In the low-pressure venting (“LPV”) stage 712, the adsorption bed 500 isvented to low pressure through the feed end 560 of the adsorption bed500. The vacuum in the exhaust groove of the feed rotary valve shoe 512communicates with the exhaust passage and the feed end 560 of theadsorption bed 500 (via the outgoing feed port and outgoing feedpassage) to draw the regeneration exhaust gas out of the adsorption bed500. The low pressure venting step 712 occurs without introduction ofoxygen enriched gas because the exhaust passage is in communication withthe outgoing feed port and the purge channel is not in communicationwith the incoming product port.

In the counter-current purge and low-pressure venting (“LPV”) stage 714,oxygen enriched gas is introduced into the product end 550 of theadsorption bed 500 in the manner described above in stage 710concurrently with the feed end 560 of the adsorption bed 500 beingvented to low pressure as was described in the above step 712.Counter-current purge is introduced into the product end 550 of theadsorbent bed 500 through fluid communication with the product end 550of a second adsorption bed 500. Oxygen enriched gas flows from theproduct end 550 of the second adsorption bed 500 through passages ofproduct port plate 557 and passages of product manifold 575. The gasfurther flows through purge channels and purge passages, of the productvalve shoe 556 through the purge channel, through the incoming productport, through the incoming product passage, through the product line,and into the product end 550 of adsorption bed 500. Because the exhaustpassage is also in communication with the outgoing feed port during thestage 714, oxygen enriched gas flows from the product end 550 to thefeed end 560, regenerating the adsorption bed 500. The vacuum in theexhaust groove of the feed rotary valve shoe 512 communicates with theexhaust passage and the feed end 560 of the adsorption bed 500 (via theoutgoing feed port and outgoing feed passage) to draw the regenerationexhaust gas out of the adsorption bed 500. From the exhaust passage, theexhaust gas flows through the vacuum ports, into the vacuum chamber, andout the vacuum pressure line. In alternative embodiments, the vacuum maybe replaced with a low-pressure vent that is near atmospheric pressureor another pressure that is low relative to the feed pressure. In someembodiments, product gas from the low pressure oxygen reservoir 129 isused to purge the product end 550 of the adsorbent bed 500.

In the first equalization-up stage 716, the product end 550 of the bed500, which is at a very low pressure, is equalized with the product endof another bed, which is at a high pressure, to bring the adsorption bed500 to a higher, intermediate pressure. The product ends 550 communicatethrough the equalization channels of product valve 556, passages ofproduct port 557 and passages of product manifold 575.

In the second equalization-up stage 718, the product end 550 of the bed500, which is at an intermediate pressure, is equalized with the productend of another bed, which is at a higher pressure, to bring the productend 550 of the bed 500 further up to an even higher pressure than instage 716. Similar to the first equalization-down stage 706, the productends 550 communicate through equalization channels of product valve 556,passages of product port plate 557 and passages of product manifold 575.

It should be noted that in some embodiments, the combined duration offeed stages 702, and 704 may be substantially the same as the combinedduration of purge stages 710, 712, and 714, which may be substantiallythree times the duration of each equalization stage 706, 708, 716, and718. In alternative embodiments, the relative duration of the feedstages 702, and 704, the purge stages 710, 712, 714, and each of theequalization stages 706, 708, 716, and 718 may vary.

After the second equalization-up stage 718 has been completed, a newcycle begins in the adsorption bed 500 starting with thepre-pressurization step 702.

The example five-bed concentrator 114 described herein, and the cycle ofexample process 700 described herein, have a number of advantages overconventional concentrators and associated cycle processes employed inthe past. The multiple equalization stages 716, and 718 at the productends 550 and the pre-pressurization stage 702 contribute to thepre-pressurization of the adsorption beds 500 prior to product delivery.As a result, the beds 500 reach their ultimate pressure (substantiallyequal to the feed pressure) quickly, and thus enable maximum utilizationof the adsorbent media. Additionally, pre-pressurizing the adsorbentbeds 500 allows product to be delivered at substantially the samepressure as the feed, thus retaining the energy of compression in thestream, which makes the product stream more valuable for use indownstream processes. In alternative embodiments, pre-pressurizing thebeds 500 with product before exposing the feed end 560 of the bed 500 tothe feed stream substantially eliminates any pressure drop experienceddue to the fluid interaction or fluid communication between two or moreadsorbent beds 500 on the feed end 560. Additionally, compared tosystems with greater numbers of beds, use of a 5-bed system, such as thesystem described herein, reduces the duration and number of beds thatare in fluid communication with the feed channels at the same time, thusreducing the propensity for fluid flow between adsorption beds. Becausefluid flow between adsorption beds is associated with a reversal of theflow direction in the higher pressure bed (resulting in decreasedperformance), reduction of this effect is advantageous.

A further advantage of a 5-bed system over other commercial systems isthat it includes a small number of adsorption beds 500, allowing theconcentrator to be relative small, compact, and light-weight, whiledelivering sufficient flow and purity and maintaining high oxygenrecovery. Other oxygen delivery modules (PSA systems), e.g., typicallythose with a small number of adsorption beds, result in deadheading thecompressor (thus resulting in high power use) during a portion of thecycle. Deadheading the compressor eliminates detrimental flow betweenthe feed side 560 of the two or more adsorption beds 500 but increasessystem power. 5-bed system eliminates compressor deadheading andminimizes performance-limiting feed side 560 flow between adsorbent beds500.

Use of the multiple pressure equalization stages 706, 708, 716, and 718reduces the amount of energy of compression required to operate theconcentrator 114. Equalizing the beds 500 conserves high-pressure gas bymoving it to another bed 500 rather than venting it to the atmosphere orto a vacuum pump. Because there is a cost associated with pressurizing agas, conserving the gas provides a savings and improves recovery. Also,because a bed 500 may contain gas enriched with product, usually at theproduct end 550 of the bed 500, allowing this gas to move into anotherbed 500, rather than venting it, conserves product and improvesrecovery. The number of equalizations is, in some embodiments, betweenone and four. It should be noted that each equalization processrepresents two equalization stages, namely, an equalization-down stageand an equalization-up stage. Thus, two equalizations means two downequalizations and two up equalizations, or four total equalizations. Thesame is true for other-number equalizations. In some embodiments, one tofour equalizations processors (two to eight equalization stages) areused in each cycle. In some embodiments, one to three equalizationsprocesses (two to six equalization stages) are used in each cycle. Insome embodiments, two equalizations processes (four equalization stages)are used in each cycle.

In alternative embodiments, the concentrator 114 may have other numbersof adsorption beds 500 based on the concentration of the feed stream,the specific gases to be separated, the implementation of the pressureswing adsorption cycle, and operating conditions. For example, but notby way of limitation, under some circumstances it may be advantageous touse four-bed concentrators or six-bed concentrators. When operating acycle similar to that described above with a four-bed concentrator, theproblem of fluid communication between the feed channels and more thanone adsorption bed (at one instant) is generally eliminated. When thefeed-end fluid communication is eliminated, the feed stages 702, and 706(depicted in FIG. 9) occur in a more desirable fashion resulting inimproved recovery of the desired product. The advantages of a six-bedsystem, compared to a five-bed system, are realized when thepressure-swing cycle described above is modified so that there are threeequalization up stages and three equalization down stages instead of twoequalization up stages and two equalization down stages. A thirdequalization is advantageous when the feed gas is available at highpressure. The third equalization conserves compressor energy because itallows the equalized beds to obtain substantially 75% of the feedpressure compared to substantially 67% of the feed pressure when twoequalization stages are used. In any PSA cycle, whenever anequalization-up operation/stage occurs, there is a correspondingequalization down operation that needs to be performed. The requirementof matching equalization stages imparts some restrictions on therelative timing of the cycle stages. If, for example, the duration ofthe feed stage is substantially the same as the duration of eachequalization stage then a six-bed cycle would provide the requiredmatching of equalization stages.

B. Energy Source and Communication Functionality

To properly function as a lightweight, portable system, the system 100schematically depicted in FIG. 1A needs to be energized by a suitableenergy source, such as the energy source 104 shown in FIG. 1A. In someembodiments, the energy source 104 may include a rechargeable batterysuch as a lithium-ion type rechargeable battery. In someimplementations, the system 100 may be powered by a portable energysource other than a lithium-ion battery. For example, a rechargeable orrenewable fuel cell may be used. Although the system is generallydescribed as being powered by a rechargeable battery, the system 100 maybe powered by multiple batteries. Thus, as used herein, the word“battery” includes one or more batteries. Further, a rechargeablebattery constituting at least part of the energy source 104 may compriseone or more internal and/or external batteries. The energy source (alsoreferred to as a battery module when the energy source includes abattery) may be removable from the system 100. In some embodiments, thesystem 100 may use a standard internal battery, a low-cost battery, anextended-operation internal battery, and an external secondary batteryin a clip-on module. Thus, in some embodiments, an oxygen deliverydevice, such as the system 100, may include an internal battery topower, at least partly, the oxygen delivery device. In suchimplementations, the internal battery located within a housing of theoxygen delivery device. The oxygen delivery device may also include anexternal battery pack secured to the housing of the oxygen deliverydevice to supplement power requirements of the oxygen delivery device.

In some implementations, the system 100 may have a built-in adapterincluding battery charging circuitry 130 and one or more plugs 132 (bothdepicted schematically in FIG. 1B) configured to allow the system 100 tobe powered from a DC power source (e.g., car cigarette lighter adapter)and/or an AC power source (e.g., home or office 110 VAC wall socket)while a battery-based energy source 104 is simultaneously being chargedfrom the DC or AC power source. The adapter or charger could alsoconstitute separate accessories. For example, the adapter may be aseparate cigarette lighter adapter used to power the system 100 and/orcharge the battery in an automobile. A separate AC adapter may be usedto convert the AC from an outlet to DC for use by the system 100 and/orcharge the battery. Another example of an adapter may be an adapter usedwith wheel chair batteries or other carts.

In some embodiments, the device may include a power supply, such as anAC/DC power supply which may be external or internal to the device.However, in certain instances, an external power supply may be provided.

Accordingly, in some embodiments, an oxygen delivery device may furtherinclude an internal DC/DC power converter placed within a housing of theoxygen delivery device and/or may further include a cart to hold theoxygen delivery device, an AC adapter external to a housing of theoxygen delivery device, with the AC adapter being mounted on the cart.Such a device may also include a battery pack external to the housing ofthe oxygen delivery device, the battery pack being mounted on the cart.

Power supplies may generate large amounts of heat and can be heavyrelative to the total weight of the device. This can cause increasedrequirements for electrical safety, thus increasing the cost of theoverall device. Additionally, an external power supply can get lost andmay make the device awkward to transport. Hence, in some embodiments, anAC and/or DC power supply may be mounted inside of a casing of a device,such as within the power bus.

For example, a power supply, such as an internal AC adapter, may bebuilt into a main body, e.g., mounted inside, of the oxygen deliverydevice. Thus, in such embodiments, an oxygen delivery device may furtherinclude an internal AC adapter placed within a housing of the oxygendelivery device. Additionally, in certain embodiments, an internal DCconverter, such as a 12V to 24V DC/DC boost converter may be positionedinside the concentrator. In certain instances, a universal power input,along with the necessary electronics to convert voltage from an externalsource (e.g., AC/DC/Airplane) may be positioned inside of oxygenconcentrator. Such a configuration may preclude the need for a separatedevice that a patient needs to carry around and keep track of. This willprevent the power supply from getting lost and may make the systemeasier to transport. Accordingly, in such implementations, an oxygendelivery device may be provided that includes a universal power adapterconfigured to connect to a plurality of power outlet types and to adaptpower delivered from the plurality of power outlet types to produce anoutput power with power characteristics required for operation of theoxygen delivery device. Such a universal power adapter may be disposedwithin a housing of the oxygen delivery device.

In some embodiments, an oxygen delivery device of the disclosure mayinclude, e.g., in addition to a built in battery, a strap-on battery.For example, in certain embodiments, an internal battery may beincluded, wherein the battery is of a sufficient in size to handle shorttrips between location where external power connectable to the oxygendelivery device is available. Although these batteries may be relativelysmall, in certain instances, they may be relatively large to allow forincreased operating time. Such a battery may have a capacity rangingfrom 40-400 Watt-hours. The physical size of a battery with saidcapacity would vary dependent on battery chemistry-utilized, but inembodiments utilizing lithium-ion rechargeable cells would occupy avolume of 0.072 to 0.722 liters and weigh 204 to 2.04 kilograms Yet,when a longer operating time on battery is useful, the oxygen deliverydevice may be connected to an external battery pack to supplement theinternal power supply.

In some implementations, an oxygen delivery device may include anindicator configured for displaying actual battery time remaining.Accurate battery capacity can be determined and calibrated, whichcalibration will allow the device to display actual battery timeremaining. This will help a subject to adequately gauge the amount oftime until connection to an alternate power source is required.Accordingly, an oxygen delivery device may be provided that includes auser interface including an indicator to indicate time remaining for abattery-based power source included with the oxygen delivery device.Additionally, in some embodiments, the device may include a backupbattery that may be employed to power a buzzer and/or an indicatorlight, such as an LED, which buzzer and/or light may be used to indicatea change in power supply, such as a loss of power.

In some embodiments, the oxygen delivery device may include one or moreUSB ports. The one or more USB ports may enable configuration of theoxygen delivery device in host/salve arrangements, e.g., a USB interfacewill allow for data acquisition and transmission to and from the oxygendelivery device, as well as software upgrades while the host interfacefacilitates further sensor connections. This allows for increased datatransferring speed. Accordingly, in some implementations, an oxygendelivery device may be provided that includes a device interface moduleincluding one or more universal serial bus (USB) ports to enable theoxygen delivery device to function as one of, for example, a slaveand/or a host when connected to at least one external device. The one ormore USB ports of the device interface module enable the oxygen deliverydevice to perform one or more of, for example, communicating data to andfrom the at least one connected external device, upgradingsoftware-based implemented functionality of at least one operation ofthe oxygen delivery device, and/or connecting to one or more sensorsconfigured to measure one or more of, for example, environmentalconditions, operating conditions of the oxygen delivery device, and apatient's therapeutic conditions.

The oxygen delivery devices described herein may also be configured forinteroperability with additional devices. Accordingly, in someimplementations, an oxygen delivery device may be provided that includesa device interface module configured to interface with one or moreadditional devices to enable interoperability functionality of theoxygen delivery device with the one or more additional devices. Theinteroperability functionality includes one or more of, for example,directing power/energy from a power source of the oxygen delivery deviceto the one or more additional devices, and/or communicating data betweenthe oxygen delivery device and the one or more additional devices. Theone or more additional devices may include one or more of, for example,pulse oximeter, pedometer, mathemoglobin monitor, carboxyhemoglobinmonitor, total hemoglobin sensor, a wireless telephone, a wirelessmodem, a remote computing device, and/or a respiration monitor. Thedevice interface module may include at least one dedicated port tointerface with at least one of the one or more additional devices.

The telemetry mechanism (also referred to as a modem or communicationmodule) of the oxygen delivery device may be used to communicatephysiological information of the user such as, without limitation, heartrate, oxygen saturation, respiratory rate, blood pressure, EKG, bodytemperature, inspiratory/expiratory time ratio (I:E ratio) with one ormore remote computers. The telemetry mechanism may also be used tocommunicate other types of information, such as, but not by way oflimitation, oxygen usage, maintenance schedules on the system 100, andbattery usage, to one or more remote devices (e.g., remote computers).

Because the system 100 is small and light (e.g., 2-15 pounds), thesystem 100 may simply be lifted from a cradle (where a cradle can beused) and readily be carried, e.g., with a shoulder strap, by an averageuser to the destination. If the user is unable to carry the system 100,the system 100 may be readily transported to the destination using acart or other transporting apparatus. Alternatively, in someembodiments, the system 100, where the system includes a built-inadapter, power may be drawn from power sources such as a car cigarettelighter adapter and/or an AC power outlet available at the destination.Further, spare battery packs 104 may be used for extended periods awayfrom standard power sources.

The oxygen delivery device therefore may be operatively coupled to avariety of accessories that require power and/or may be configured(e.g., through programming) to allow the oxygen delivery device toexchange information therewith. For example, the oxygen delivery devicemay be configured to be coupled to a device for the purpose of receivinginformation therefrom. Hence, the devices and systems described hereinmay allow for the collection and/or transmission of clinical data, whichcan be reported to clinicians, electronic medical record repository, orcaregiver. Such information can be processed by the controller so as tooptimize the manner in which oxygen is delivered to the subject.Auxiliary devices may include one or more of a pulse oximeter,pedometer, methemoglobin monitor, carboxyhemoglobin monitor, totalhemoglobin sensor, wireless phone, wireless modem, and/or respirationmonitor and the like. Hence, the power supply of the concentrator may beconfigured to serve as a power source for one or more of these auxiliarydevices.

If the battery pack connected to the energy source 104 includes multiplebatteries, the system (oxygen delivery device) 100 may include a batterysequencing mechanism to conserve battery life.

C. Output Sensor

With reference to FIGS. 1A and 1B, and 10, one or more output sensors106 are used to sense one or more conditions of the user 108,environment conditions, operational conditions of the oxygen deliverydevice, etc., to determine, among other things, the oxygen flow rateneeds of the user and, hence, the oxygen flow rate output requirementsfor the system 100. The control unit (controller) 110 is linked to theone or more output sensors 106, from which the control unit 110 receivesmeasured/determined data representative of the conditions being sensed.The controller is also linked to the oxygen gas generator 102 to controloxygen generation operations (including operations of the oxygendelivery module, any of the gas moving devices, etc.) in response to thecondition(s) sensed by the one or more output sensors 106. For example,the output sensor(s) 106 may include any or all of the activity sensorsshown and described in U.S. Pat. No. 5,928,189, which is incorporatedherein by reference in its entirety as though set forth in full. Theseoutput sensors include, for example, a pressure sensor 150, a positionsensor 152, an acceleration sensor 154, as well as a physiologicalcondition or metabolic sensor 156 and an altitude sensor 158.

The first three sensors 150, 152, 154 (and, in certain circumstances,the physiological condition sensor 156) are activity sensors becausethese sensors provide signals/data representing activity of the user108. In the delivery of oxygen using a portable oxygen concentrationsystem, it is important to deliver an amount of oxygen gas proportionalto the activity level of the user 108 without delivering too muchoxygen. Too much oxygen may be harmful for the user 108 and may depletethe energy source 104 (e.g., reduces the life of a battery comprisingthe energy source 104). The control unit 110 (which, in someembodiments, may be implemented using a programmable processor-basedcontroller) is configured to regulate the oxygen gas generator 102 tocontrol the flow rate of oxygen gas to the user 108 based on the one ormore signals representative of the activity level of the user producedby the one or more sensors 106. For example, if the output sensor(s) 106indicates that the user 108 has gone from an inactive state to an activestate, the control unit 110 may cause the oxygen gas generator 102 toincrease the flow rate of oxygen gas to the user 108, e.g., by causingthe speed of a gas moving device delivering air to the oxygen deliverymodule of the oxygen gas generator to increase, and/or may provide aburst of oxygen gas to the user 108 from a high-pressure oxygenreservoir. If the output sensor(s) 106 indicates that the user 108 hasgone from an active state to an inactive state, the control unit 110 maycause the oxygen gas generator 102 to reduce the flow rate of oxygen gasto the user.

As noted, in some embodiments, the amount of oxygen gas supplied iscontrolled by controlling the speed of the motor 118 of the gas movingdevice (compressor) via the variable-speed controller 119 describedherein.

Alternatively, or in addition to the variable-speed controller, thesupply of oxygen gas may be controlled by the supply valve 160 locatedin the supply line 121 between the oxygen gas generator 102 and the user108. For example, the supply valve 160 may be variably movable betweenat least a first position and a second position, the second positionallowing a greater flow of concentrated gaseous oxygen through than thefirst position. The control unit 110 may cause the supply valve 160 tomove from the first position to the second position when one or more ofthe activity level sensors 152, 154, and 156 sense or determine anactive level of activity of the user 108. For example, the control unit110 may include a timer, and when an active level is sensed for a timeperiod exceeding a predetermined timed period, the control unit 110causes the valve 160 to move from the first position to the secondposition.

Examples of pressure sensors 150 include, without limitation, a footswitch that indicates when a user is in a standing position compared toa sedentary position, and a seat switch that indicates when a user is ina seated position compared to a standing position.

A pendulum switch is an example of a position sensor 152. For example, apendulum switch may include a thigh switch positioned pendulously toindicate one mode when the user is standing, i.e., the switch hangsvertically, and another mode when the user seated, e.g., the thighswitch being raised to a more horizontal position. A mercury switch maybe used as a position sensor.

An acceleration sensor 158 such as an accelerometer is another exampleof an activity sensor that provides a signal representing activity ofthe user.

The physiological condition or metabolic sensor 156 may also function asan activity sensor. The physiological condition sensor 156 may be usedto monitor one or more physiological conditions of the user forcontrolling the oxygen gas generator 102, or for other purposes.Examples of physiological conditions that may be monitored with thesensor 156 include, but without limitation, blood oxygen level, heartrate, respiration rate, blood pressure, EKG, body temperature, and I toE ratio (the inspiration to expiration ratio). An oximeter, such as theoximeter 153 depicted in FIG. 10, is an example of another sensor tomonitor conditions of the patient that may be used in the system 100.The oximeter measures the blood oxygen level of the user, upon whichoxygen production may be at least partially based. Other types ofsensors to monitor conditions of the patient (e.g., therapeuticconditions) may also be included.

An altitude sensor 158 is an example of an environmental or ambientcondition sensor that may sense an environmental or ambient conditionupon which control of the supply of oxygen gas to the user may be atleast partially based. The altitude sensor 158 may be used alone or inconjunction with any or all of the above sensors, the control unit 110and the oxygen gas generator 102 to control the supply of oxygen gas tothe user in accordance with the sensed altitude or elevation. Forexample, at higher sensed elevations, where air is less concentratedwith oxygen, the control unit may increase the flow rate of oxygen gasto the user 108. At lower sensed elevations, where air is moreconcentrated, the control unit may decrease the flow rate of oxygen gasto the user 108 or maintain it at a control level. Other types ofsensors to monitor environmental conditions that may also impactoperation of the oxygen delivery device, e.g., sensors to monitorambient temperature, may also be coupled to the controller 110, or toanother controller.

In some embodiments, the concentrator may be configured for the remotemonitoring of peripheral oxygen saturation (SpO2), for instance, so asto provide a closed loop O2 delivery. For example, an oxygen deliverydevice/concentrator, such as any of the concentrators described herein,may be configured to employ a sensor, such as a pulse oximeter, tomonitor a subject's oxygen saturation. The output level of the oxygendelivery device can then be adjusted to deliver a level of oxygen thatmore precisely meets the needs of the subject given a particular oxygensaturation. For instance, a pulse oximeter may be operatively connected,e.g., via a wired or wireless communications link to the controller,which controller may in turn use data provided by the sensor to controlthe output level of the oxygen to be delivered so as to be in accordancewith a particular oxygen saturation requirement for a subject.Accordingly, in some embodiments, an oxygen delivery device is providedthat includes an oxygen delivery module to produce at least concentratedoxygen, and a gas moving device (e.g., a compressor) to deliver air tothe oxygen delivery module, with the gas moving device being driven by amotor to actuate the gas moving device. In such embodiments, the oxygendelivery device also includes a communication module to communicate witha remote sensor, e.g., a remote pulse oximeter, configured to determineperipheral oxygen saturation of a patient, and a controller to controloperations of at least one of the oxygen delivery module and the gasmoving device based, at least in part, on the determined peripheraloxygen saturation, to adjust the oxygen purity level of the oxygenproduced by the oxygen delivery module to cause the peripheral oxygensaturation level of the patient to converge to a pre-determined requiredperipheral saturation level.

For example, an oximeter sensor may be secured to the subject, such asto secure the remote oximeter sensor to the fingertip or earlobe of thesubject, and the oximeter may thus be configured to determine the changein light absorbance by the patient's tissue. Particularly, a light, suchas a light containing both red and infrared wavelengths, is passed fromone side to the other. The change in absorbance of the wavelength isthen measured. This will allow for a determination of the light'sabsorbance due to the pulsing arterial blood alone, exclusive of venousblood, skin, bone, muscle, fat, and the like. Based upon the ratio ofthe change in absorbance of the red and infrared light caused by thedifference in color between oxygen-bound (bright red) and oxygen unbound(dark red) blood hemoglobin, the oxygenation (e.g., % of hemoglobinmolecules bound with oxygen molecules) of the blood may be determined.This information may then be communicated, e.g., via wirelesscommunication, to the controller of the oxygen delivery device, whichmay then adjust the purity and/or flow level of the oxygen beingdelivered so as to achieve a particular saturation level.

For instance, a target oxygenation (e.g., saturation) level may be inputto the controller or otherwise set, e.g., via a user interface, via acommunication module receiving data transmitted from a remote locationthat indicates the target oxygenation level, etc. The pulse oximetersensor will measure the level of saturation and communicate thedetermined data to the controller of the oxygen delivery device. If theoxygenation is below the selected level, e.g., 90%, the controller willcause an increase in the level of oxygen (e.g., purity, flow) in theflow being delivered to the subject. The system will then recheck thepulse oxygenation to determine if the desired, saturation has beenreached. If not, the process will repeat until the selected oxygenationhas been achieved. Once a particularly selected oxygenation level hasbeen achieved, the system may be configured for periodic monitoring ofthe oxygenation level so as to ensure that level is maintained. In amanner such as this, the amount of time a subject spends at optimalsaturation may be regulated so as to help prevent treatmentexacerbations and to minimize the amount of power consumed by the oxygendelivery device, thus maximizing battery life.

Accordingly, with reference to FIG. 11, a flow chart of an exampleembodiment of a procedure 800 to control oxygenation level of a patientis shown. The procedure 800 includes receiving 810 data representativeof peripheral oxygen saturation of a patient, the data beingcommunicated from a remote sensor (such as a remote pulse oximeter)configured to determine the peripheral oxygen saturation of the patient.Having received the data representative of the peripheral oxygensaturation of the patient, operations of at least one of an oxygendelivery module (e.g., PSA, VPSA, etc.) and a gas moving device (e.g., acompressor) of an oxygen delivery device are controlled based, at leastin part, on the data representative of the determined peripheral oxygensaturation of the patient, to adjust the oxygen purity level of theoxygen produced by the oxygen delivery module to cause the peripheraloxygen saturation level of the patient to converge to a pre-determinedrequired peripheral saturation level.

In some implementations, one or more sensors may be provided so as tocontinuously monitor the breathing pattern of a subject in either pulsedose or continuous flow modes. For instance, when a subject is operatingthe device in a pulsed dose mode, the controller may be configured(e.g., through computer instructions where the controller is aprogrammable processor-based device) to determine a subject's breathingand/or ensuring that a pulse of oxygen is delivered periodically inaccordance with a predetermined breathing pattern. The controller canalso then be employed to determine and ascertain that the desired pulseis in fact delivered. This is important because if the subject does notbreathe and/or the desired pulse is not delivered that may mean that thesubject might not be getting the oxygen needed. In such an instance, theconcentrator may be configured to change modes to continuous flow toensure that the appropriate level of oxygen is being delivered to thesubject.

For example, in some embodiments, such as when a subject is talking,when the cannula has been dislodged, or when a subject breathes throughits mouth, an inspiration sensor, e.g., a sensor detecting air pressure,may not be able to detect inspiration. Therefore, by implementing aprocedure for continuous flow breath detection, the concentrator canchange modes back to pulsed dose mode if it detects that a subject hasresumed breathing and it is safe to resume pulse dose mode. This willhelp to extend operating time on battery, because the pulse dose moderequires less power than does the continuous flow mode of delivery.

For example, if a subject stops breathing or no trigger is sensed, thepulse dose mode that may be activated may be turned off for a period oftime to revert to continuous flow, which in turn may be turned off torevert back to pulse dose mode once normal breathing has been detected.Further, such a configuration can help ensure that the subject'ssaturation level is maintained even when they are talking or breathingfrom their mouth, such as by sensing the breath in pulse or continuousmode and regulating the delivery accordingly.

Accordingly, in some implementations, an oxygen delivery device isprovided that includes an oxygen delivery module (e.g., a pressure swingadsorption system, a vacuum-pressure swing adsorption system, a vacuumswing adsorption system, a membrane separation device, etc.), and atleast one sensor to detect patient breathing. In some embodiments, theat least one sensor may include, for example, a pressure sensor fluidlyconnected to a cannula, coupled to the oxygen delivery module, that isstructured to deliver the oxygen from the oxygen delivery module throughthe patient's nasal passages. The pressure sensor fluidly connected to acannula is configured to detect pressure changes within the patient'snasal passages, and to generate data representative of the pressurechanges.

The oxygen delivery device also includes a controller configured tocontrol the oxygen delivery module to cause the oxygen delivery moduleto deliver oxygen to the patient based, at least in part, on data fromthe at least one sensor such that in response to a determination, basedon data from the at least one sensor, that no breathing is detected fora first pre-determined period of time, the controller causes the oxygendelivery device to deliver oxygen to the patient in continuous flowmode. The controller is also configured to subsequently (i.e., afterswitching to the continuous flow mode), in response to a determination,based on data from the at least one sensor, that breathing is detectedfor a second pre-determined period of time, the controller causes theoxygen delivery device to revert back to pulse mode to thus cause oxygento be delivered to the patient in a pulse flow mode. In someembodiments, the restoration of pulse mode in oxygen delivery may occurafter some pre-determined time period (e.g., 5 minutes, 10 minutes) haselapsed. In some embodiments, determination of when breathing has resumemay be performed by processing (filtering) data received from a sensorsensing pressure to determine onset of an inspiratory cycle for thepatient. Such filtering may enable early detection/determination of thebeginning of the patient's inspiratory cycle, to thus revert tocontinuous flow mode more expeditiously (which in turn would reducepower consumption requirements). Such filtering may utilize, forexample, time averaging methods or low pass methods.

With reference now to FIG. 12, a flow chart of an example procedure 850to enable continuous breathing monitoring and control of oxygen deliverymodes is shown. Initially, oxygen may be delivered in pulse mode, anddata regarding patient breathing is received 860. For example, acontroller controlling operation of the oxygen delivery device mayreceive data from a pressure sensor connected to a cannula through whichoxygen is delivered. Based on the received information, oxygen deliveryto the patient is controlled 870 by causing an oxygen delivery module todeliver oxygen to the patient in continuous mode flow in response to adetermination, based on the received information, that no patientbreathing is detected for a first pre-determined period of time (e.g.,30 second, 60 seconds, or some other period of time). Additionally, inresponse to a determination, based on data from the at least one sensor,that breathing is detected for a second period of time, the controllercauses termination of the continuous flow mode, and further causes theoxygen delivery module to deliver oxygen to the patient in a pulse flowmode. In some embodiments, pulse mode may also be restored after somepre-determined period of time has elapsed (e.g., 5 minutes, 10 minutes,etc.)

In addition, in some embodiments, when a patient is in continuous modeand starts to exercise, a continuous monitor of breathing pattern incontinuous flow would allow the system to change the continuous settingto match the breathing pattern. For example, if a patient is prescribed1 lpm continuous flow at a resting BPM of 15, the system can detect the15 bpm and maintain 1 lpm. If the patient's BPM goes to 25 BPM, thesystem can automatically change the continuous setting to a higher flowvalue for 25 BPM.

Additional or different sensors may be used to sense a condition uponwhich control of the supply of oxygen gas to the user may be at leastpartially based. Further, any or all of the embodiments described abovefor regulating the amount of oxygen gas supplied to the user 108, i.e.,variable-speed controller 119, supply valve 160, (or alternativeembodiments) may be used with the one or more sensors and the controlunit 110 to control of the supply of oxygen gas to the user 108.

In some implementations, a sensor may also be provided so as to detectone or more problems with respect to one of the filters of the device.For example, a sensor may be provided so as to determine a possiblefaulting intake filter. A dirty intake filter may choke the flow of airto the compressor and thus adversely affect the concentrator such as bycausing an incomplete PSA cycle. An incomplete PSA cycle may in turnlead to water buildup on the adsorbent bed which may result in adegradation of system performance. Consequently, a sensor for detectingwhen a filter, such as an intake filter, has become dirty may alert auser of the need to change or clean the filter, for example, when agiven differential pressure across the filter has been reached whichsignals that the filter may be dirty. Such a configuration could beuseful in prolonging the life of the compressor and/or oxygen deliverymodule.

Accordingly, in some embodiments, an oxygen delivery device may beprovided that includes an oxygen delivery module (e.g., PSA, VPSA,etc.), at least one sensor to determine data representative ofperformance degradation of one or more filters used with the oxygendelivery device, and a controller (such as the controller 110 depictedin FIG. 1A and FIG. 10) to alert, based on the determined datarepresentative of the performance degradation of the one or morefilters, that performance of at least one of the one or more filters hasdegraded. As noted, in some embodiments, the one or more filters mayinclude an intake filter to filter ambient air drawn into a gas movingdevice, where the at least one sensor is configured to determinepressure differential across the intake filter, and where the controlleris configured to alert that the performance of the intake filter hasdegraded in response to a determination that the determined pressuredifferential across the intake filter exceeds a pre-determined pressuredifferential threshold. With reference to FIG. 13, a flow chart of anexample procedure 900 to monitor and control filter performance isshown. The procedure 900 includes measuring 910 pressure differentialacross an intake filter configured to filter ambient air drawn into agas moving device. A determination is then made 920 as to whether themeasured pressure differential across the intake filter exceeds apre-determined pressure differential threshold. In response to adetermination that the measured pressure differential across the intakefilter exceeds the pre-determined pressure differential threshold, analert that performance of the intake filter had degraded is made 930.

In some implementations, a check valve and a gas filter may be mountedwithin the product tank. Such a tank may be designed to help keepnon-metallic parts downstream of the PSA module (e.g., tanks, tubing,filter housings, etc) from passing atmospheric moisture to the PSAmodule via permeation. For instance, the check valve 1710 and filterhousing 1720 (depicted in FIG. 29) may be positioned with respect to theproduct tank so as to provide a metallic shield that protects thedownstream components of the device from atmospheric moisture whichcannot penetrate the plastic structure typically enclosing suchcomponents. This may be useful because a configuration such as thisprevents water, e.g., in the form of humidity, from passing throughnon-metallic materials on the product end of the PSA module and attachedgas conduits thereby helping to prolong PSA module operating life.

Thus, with reference to FIG. 29, a cross-sectional diagram of an exampleembodiment of an assembly 1700 including the check valve 1710 andintegrated filter assembly 1720 is shown. The assembly 1700 thusincludes a check valve and gas filter included within a housing of anoxygen delivery device and positioned downstream of the oxygen deliverymodule. As noted, the check valve and gas filter are configured toprevent moisture present in components of the oxygen delivery devicelocated downstream of the oxygen delivery module from entering theoxygen delivery module.

D. Control Unit

With reference to FIG. 14, a block diagram of an arrangement of at leastsome of the components/units/modules of an example embodiment of anoxygen delivery device (oxygen concentration system) is shown. Thecontrol unit 110 (also depicted in FIGS. 1A and 1B) may be constitutedin various configurations, and may include, for example, a centralmicroprocessor or CPU 162 in communication with the components of thesystem described herein via one or more interfaces, controllers, portsor other electrical circuit elements for controlling and managing thesystem. The system 100 may include a user interface 111 that constitutesa part of the control unit 110, or the user interface may be coupled tothe control unit 110 to enable the user, provider, doctor, etc., toenter information, e.g., prescription oxygen level, flow rate, activitylevel, etc., to facilitate controlling of the system 100.

While the CPU 162 is shown to be coupled to the various sensors depictedin FIG. 14, and to also be coupled to other units/components of anoxygen delivery device, in some embodiments, additional controllers,separate from the controller implemented using the CPU 162, may be usedto separately and/or independently control any of the units/componentsdepicted in FIG. 1. For example, separate controllers may be coupled toany number of the depicted sensors (to enable receipt and processing ofdata received from those sensors, and/or to control those sensors). Suchcontrollers (or just the single controller implemented using the CPU162) may also be coupled to additional components/units (such asadditional sensors) not specifically depicted in FIG. 14, or in any ofthe other figures provided herein.

In some embodiments, it is useful to control the purity of oxygen in theflow from the device to the subject. For example, depending on asubject's complications, the delivery of oxygen at or above a givenpurity level may be required. However, in certain instances, it may beuseful to deliver oxygen at the lower end of the acceptable range, forexample, in those situations where the conservation of energy is ofconcern. Hence, by controlling oxygen purity to the lower end of theacceptable range of therapy, less power is consumed.

Accordingly, the controller may be configured to receive informationpertaining to the acceptable purity range that may be delivered. One ormore sensors, e.g., a flow/purity sensor, may be provided so as todetermine the purity of the oxygen being delivered to the subject. Thisdata may be sent to the controller. If the purity is above a given setpoint, for instance, above the lower range of what is acceptable forthat subject, e.g., 90% purity, then the controller can adjust theoperation of the system so as to down regulate the purity beingdelivered to the lower limit. For example, regulation of the purity ofthe generated oxygen can be performed by controlling the compressor'spressure, by controlling the ATF valve speed, etc. As less power isrequired for delivering oxygen at the lower purity limit, this modeconserves power, thereby allowing longer duration on battery. If thepurity is below the acceptable level, the controller may then upregulate the system so as to ensure the oxygen being delivered is atleast at the minimum required purity.

Thus, in some implementations, an oxygen delivery device is providedthat includes an oxygen delivery module (e.g., PSA, VPSA, etc.) toproduce at least concentrated oxygen at a controllable purity level fromair, a gas moving device (e.g., a compressor) to deliver the ambient airto the oxygen delivery module, and at least one controllable motor tocontrollably drive the gas moving device. The oxygen delivery devicefurther includes an energy source (a battery, such as a rechargeablebattery, an external power source whose power is adapter by an adapterto the power requirements of the oxygen delivery device) to power the atleast one controllable motor, a pressure sensor to determine a pressurelevel produced in the oxygen delivery device, a purity sensor todetermine oxygen purity value produced by the oxygen delivery module. Acontroller of the oxygen delivery device is configured to control basedon the determined oxygen purity value and the pressure level, at leastthe gas moving device's operations and the oxygen delivery module'soperations so as to cause the pressure resulting from the operation ofthe gas moving device to be substantially at a pre-determined pressurevalue and to cause the purity level of the oxygen produced by the oxygendelivery module to be substantially at a pre-determined purity value. Insome embodiments, the controller is configured to cause the pressureresulting from the operation of the gas moving device to besubstantially at the pre-determined pressure value and to cause thepurity level of the oxygen produced by the oxygen delivery module to besubstantially at the pre-determined purity value in response to adetermination that an energy source to power the oxygen delivery deviceis a battery (and thus it becomes more important to conserve theavailable power by controlling the oxygen delivery device to operate atthe pre-determined oxygen purity level and/or the pre-determinedpressure level).

The pre-determined pressure value may correspond to a minimum acceptablepressure level, e.g., between approximately 3-7 psig pressure, and thepre-determined purity value may correspond to a minimum acceptableoxygen purity level, e.g., between approximately 82-93% oxygen, suchthat energy consumption of the system is reduced.

With reference to FIG. 15, a flow chart of an example embodiment of aprocedure 950 to control operations of an oxygen delivery device basedon measured oxygen purity and pressure values is shown. The procedure950 includes receiving 960 data representative of oxygen purity value inan oxygen delivery module from a purity sensor, and receiving 970 from apressure sensor a pressure level value produced by a gas moving deviceconfigured to draw air into the oxygen delivery module. Based on thereceived oxygen purity value and the received pressure level value, atleast one of, for example, the gas moving device's operations and/or theoxygen delivery module's operations is controlled 980 to cause thepressure resulting from the operation of the gas moving device to besubstantially at a pre-determined pressure value and to cause the puritylevel of the oxygen produced by the oxygen delivery module to besubstantially at a pre-determined purity value. Additionally, bycontrolling oxygen purity to the lower end of the acceptable range oftherapy, the pressure too can be down regulated to a minimum acceptablelevel for a selected flow to be delivered and product purge to bemaintained. This may lead to an additional reduction of operating power,thus allowing longer duration on a battery-based energy source.

In addition to controlling the purity level of oxygen being delivered,the concentrator may additionally control the pulse volume beingdelivered. For instance, depending on the needs of the subject, a pulseof oxygen may be delivered in a volume that is anywhere from about 10 mlto 270 ml, such as about 90 ml to about 195 ml, including about 100 mlto about 192 ml. For example, the concentrator may be configured so asto produce a selected purity of oxygen to be delivered in a selectedvolume at a selected rate. In some embodiments, the concentrator isconfigured to deliver up to 3 liters per minute (LPM) continuously.Accordingly, when a selected volume, e.g., 3.0 LPM, is to be deliveredin pulses, such as 192 ml per pulse, over a given time period, e.g., oneminute, the amount to be delivered per pulse and the timing of thedelivery may be controlled by the controller such that the amount perpulse is well within the range of the subject's normal breathing rate,thus ensuring that the maximum amount of oxygen is actually delivered tothe subject in a manner and at a time that the subject can use it.

For example, if 192 ml pulses are to be delivered, the number of pulsesneeded that can be supported by an oxygen delivery device that delivers3.0 liters per minute of oxygen is 3.0 LPM/0.192 mL=15.6 pulses/minute,or 15 BPM. 15 BPM is well within the normal breath rate for a typicalresting subject. When the pulse volume of oxygen delivered duringinspiration is larger, the fraction of inspired oxygen (FiO2) will bemuch higher. Therefore, simply by delivering in pulse mode, theconcentrator is able to provide a fraction of inspired oxygen (FiO2)that may be 20% higher than that achieved with continuous flow using thesame amount of power. Thus, larger pulse volumes help to increase FiO2in those ambulatory subject's that need higher pulses. In someembodiments, to increase the FiO2, the pulse may be delivered during thefirst 60% of the patient's inspiratory period, which is the time periodduring which the body absorbs most of the oxygen available in the pulse.

Accordingly, in some implementations, an oxygen delivery device isprovided that includes an oxygen delivery module (e.g., PSA, VPSA)configured to deliver a pulse including greater than 100 mL ofconcentrated oxygen, and a controller (which may be implemented as partof the control unit 110 shown in FIG. 1A) configured to control theoxygen delivery module to cause the oxygen delivery module to deliverthe pulse including greater than the 100 mL of the concentrated oxygenwithin approximately first 60% of a patient's inspiratory period. Toenable delivery of the pulse within the first 60%, it is generallyrequired to achieve early detection of the onset of the patient'sinspiratory cycle. As described herein, in some implementations, earlydetection of the onset of an inspiratory cycle is performed by receivingdata from a sensor configured to detect patient's breathing, e.g., bydetecting pressure changes within the patient's nasal passages by, forexample, using a pressure sensor placed inside the cannula used todeliver oxygen. The received data representative of such detectedpressure changes in the patient's nasal passages is processed, e.g.,applying filtering functions that determine based on the raw datawhether the inspiratory cycle has commenced.

With reference to FIG. 16, a flow chart of an example procedure 1000 todeliver oxygen pulses is shown. The procedure includes controlling 1010an oxygen delivery module (e.g., a PSA, VPSA, etc.) to cause the oxygendelivery module to deliver a pulse greater than 100 mL of concentratedoxygen. The oxygen delivery module delivers 1020 the pulse includinggreater than 100 mL of concentrated oxygen within approximately first60% of a patient's inspiratory period of a patient's breathing.

To illustrate the efficacy of delivering large boluses of oxygen,consider the following three examples. In all three examples, theInspiration:Expiration ratio (I:E) is assumed to be 1:3 (e.g.,inspiration takes 1 second, while expiration lasts 3 seconds), the tidalvolume is assumed to be 500 mL, the breath rate is assumed to be 15 BPM,and the oxygen delivery module, in these examples, produces oxygen witha purity of 92%.

In the first example, a three liter per minute continuous flow of oxygenis produced by a concentrator, equating to 50 mL/second delivered to thepatient from the oxygen delivery device. Accordingly, the percent ofoxygen in that flow is 92%×50 mL=46 mL O₂. The remainder of the tidalvolume inhaled by the patient is 450 mL of air (500 mL-50 mL deliveredby the oxygen delivery device), of which 94.5 mL (21%) is oxygen. Thus,with a continuous flow of 50 mL/second from the oxygen delivery device,the FiO2 in this example is computed to be (94.5 mL O₂+46 mL O₂)/500mL=28.1%.

In the second example, a 96 mL pulse dose is to be delivered to thepatient with each breath. The percent of oxygen in that pulse is 92%×96mL=88.32 mL O₂. The remainder of the tidal volume inhaled by the patientis 404 mL of air (500 mL-96 mL delivered by the oxygen delivery device),of which 84.84 mL (21%) is oxygen. Thus, with a pulse of 96 mL from theoxygen delivery device, the FiO2 in this example is computed to be(88.32 mL O₂+84.84 mL O₂)/500 mL=34.6%.

In the third example, a 192 mL pulse dose is to be delivered to thepatient with each breath. The percent of oxygen in that pulse is 92%×192mL=176.64 mL O₂. The remainder of the tidal volume inhaled by thepatient is 308 mL of air (500 mL-192 mL delivered by the oxygen deliverydevice), of which 64.68 mL (21%) is oxygen. Thus, with a pulse of 192 mLfrom the oxygen delivery device, the FiO2 in this example is computed tobe (176.64 mL O₂+64.68 mL O₂)/500 mL=48.2%.

Accordingly, the ability to deliver larger oxygen pulse doses to thepatient improves the FiO2 for the patient.

In some implementations, a boost mode may also be provided.Particularly, when a concentrator is operating at temperature oraltitude extremes or from a limited (or limitless) power source, theflow from the compressor/vacuum pump and cycle time of the PSA/VPSAprocess can be adjusted to operate the concentrator to most efficientlymeet a given selected therapeutic level. For example, a therapeuticlevel may be determined and prescribed by a clinician and that dataentered into the controller, which will then control the components ofthe system so as to deliver the selected, e.g., prescribed, purity ofoxygen to the subject. More specifically, a clinician may prescribe acontinuous flow rate to a subject and/or a respiratory therapist maytitrate the subject on a pulse dose machine such that the subject willhave the same pulse oxygenation as they would when using a continuousflow mode. What is desired is that the subject breathe a gas at anelevated FiO2 so that the subject's pulse oxygenation is raised.

For example, without the boost mode, the actual purity of oxygen beingdelivered at a particular temperature and/or altitude might be 89%. Theboost mode is configured for taking into account the effect thattemperature and/or altitude may have on the system by adjusting theoperations of the system so that the purity of the oxygen to bedelivered would be higher, e.g., 92 to 94% in this particular example,thus, resulting in higher FiO2. Thus, the purity may be controlled andadjusted so as ensure that a given FiO2 is delivered.

Accordingly, in some embodiments, an oxygen delivery device may beprovided that includes an oxygen delivery module (e.g., PSA, VPSA), atleast one sensor to determine at least one environmental condition(e.g., ambient temperature and/or altitude) in which the portable oxygendelivery device is operating, and a controller to control, based on thedetermined at least one environmental condition, at least the oxygendelivery module's operations to cause a specified therapeuticrequirement for the patient to be achieved.

In some embodiments, operations of the oxygen delivery device may becontrolled based on a patient's tidal volume and the patient's fractionof inspired oxygen. For example, when operating in FiO2 mode, theconcentrator may monitor BPM and purity. A physician and/or clinicianmay input to the system a target FiO2, and an approximate I:E ratio.Given these data inputs, the controller determines the optimum oxygendelivery device operating conditions (e.g., compressor speed, valvespeed, oxygen purity) to deliver that will result in reduced (and insome cases, the lowest) power being consumed, and therefore in longer(and in some cases, the longest) battery time for the desired FiO2.Thus, by determining tidal volume, e.g., having the subject blow with noforced effort into a variable volume container with a fixed backpressureand determining the amount of gas collected, and providing that tidalvolume data into the controller of the concentrator, the controller canthen adjust the system so as to deliver oxygen based upon a targetedFiO2 for the subject. The benefits of this mode of operation is toextend the operating temperature and/or altitude ranges, maximize theamount of time a subject spends at optimal saturation, help preventpatient exacerbations, minimize the amount of power consumed by theconcentrator, and maximize time on battery. This may also beaccomplished when using independent compressor and vacuum pumps.

Accordingly, in some implementations, an oxygen delivery device may beprovided that includes an oxygen delivery module (e.g., PSA, VPSA) toproduce at least concentrated oxygen, and a controller configured tocontrol the oxygen delivery module to cause the oxygen delivery moduleto deliver oxygen to a patient based on a patient's tidal volume datarepresentative of the normal volume of air displaced between inspirationand expiration by the patient, and further based on a fraction ofinspired oxygen (FiO2) value required for the patient. The controllermay thus determine operating conditions (e.g., speed of the gas movingdevice providing an air flow to the oxygen delivery module, oxygendelivery module cycle speed, and desired oxygen purity level to beproduced by the oxygen delivery device) based on the patient's tidalvolume and FiO2 values. In some embodiments, the determination ofoperating conditions may also be based also on one or more of, forexample, respiratory rate for the patient, oxygen purity value of theoxygen delivered to the patient, and/or Inspiration:Expiration (I:E)ratio. In some embodiments, the oxygen delivery device may also includea pressure sensor to determine a pressure level produced by oxygendelivery device, a gas moving device providing an air flow to the oxygendelivery module, and a purity sensor to determine oxygen purity valueproduced by the oxygen delivery device.

With reference to FIG. 17, a flow chart of an example embodiment of aprocedure 1050 to control operation of an oxygen delivery device isshown. The procedure 1050 includes, in some embodiments, receiving 1060data representative of at least a patient's tidal volume data indicativeof normal volume of air displaced between inspiration and expiration bythe patient, and data representative of a fraction of inspired oxygen(FiO2) value required for the patient. Based at least on the patient'stidal volume data and the FiO2 value, an oxygen delivery module (such aPSA or VPSA) producing at least concentrated oxygen is controlled 1070to cause the oxygen delivery module to deliver oxygen to the patient.Control of the operations of the oxygen delivery device can beperformed, for example, by controlling the speed of the compressordelivering air to the oxygen delivery module.

FIG. 18 is a flow chart of another example procedure 1100 to controloperation of an oxygen delivery device based, at least in part, on apatient's tidal volume, FiO2 value, as well as other factors, andprovides additional details on implementations to determine operationconditions for an oxygen delivery device. As noted herein, whenproviding supplemental oxygen to a patient whose respiratory conditionrequires it, the fraction of oxygen in the inspired gas is elevated fromthe normal 20.9% oxygen found in normal atmospheric composition. Thesupplemental oxygen may be delivered via a nasal cannula or similarconduit and combines with the oxygen present in inhaled air. Elevatingthis fraction of inspired oxygen (FiO2) is a process to bring aboutdesired physiologic responses in a patient. In some conventionalsystems, oxygen delivery was performed such that each liter ofcontinuous flow supplemental oxygen from an oxygen concentratordelivered to a patient via nasal cannula was approximately equivalent toincreasing the patient's FiO2 by 3%. In another conventional system,delivery of a bolus of oxygen was timed with the patient's inspiration.

The bolus of oxygen supplements the air that the patient is breathingand serves to elevate the patient's FiO2 by some amount. The amount ofsupplemental oxygen a patient required to maintain a specific FiO2varies with several factors. Among these are respiratory rate, exerciselevel, tidal volume, inspiratory time, expiratory time, and purity ofoxygen provided by the device. A drawback of conventional systems isthat they do not account for varying respiratory rates or deliveredpurity, nor do they provide direct control of oxygen delivered to apatient by varying inputs for patient tidal volume, inspiratory time, orexpiratory time. As a result, patients using oxygen delivery devicesthat utilize these methods often provide insufficient amounts of oxygento the patient.

A patient using supplemental oxygen obtains oxygen from two sources: thesupplemental source and ambient air. The total flow of gas provided tothe patient, Q_(T), is the sum of the delivered flow of gas from thesupplemental source, Q_(O2), and the flow of air, Q_(Air), as describedby Equation (1). The air flow Q_(Air) is the flow of air that isinspired by a patient during a breath.Q _(T) =Q _(O2) +Q _(Air)  (1)

Considering just the portion of these flows that are composed of oxygen,Equation (2) follows where f_(IO2) is the fraction of oxygen inspired bythe patient, F_(DO2), is the fraction of gas delivered by thesupplemental device that is composed of oxygen, and the value of 0.209represents the fraction of oxygen found in normal atmosphericcomposition.F _(IO2) Q _(T) =F _(DO2) Q _(O2)+0.209Q _(Air)  (2)

Recognizing that when supplemental oxygen is delivered to a patient, thepatient only makes use of the oxygen delivered during the inspiratoryphase of a breath (and thus, as described above, in some embodiments, anoxygen delivery device may be configured to deliver a substantialportion of the oxygen pulse in the 60% of the inspiration portion of thebreathing cycle). Accordingly, the total flow of gas inspired by apatient Q_(T) is the product of the patient's tidal volume, V_(T), andrespiratory rate, f.Q _(T) =fV _(T)  (3)

The fraction of gas that is inhaled during each breath can be expressedas β, where I is the time of inspiration and E is the time ofexpiration.

$\begin{matrix}{\beta = \frac{I}{I + E}} & (4)\end{matrix}$

Equations (1) through (4) may be combined algebraically to deriveEquation (5). Equation (5) may be used to perform the “Calculate oxygenflow rate” operation (at 1108) in the example procedure 1100 shown inFIG. 18.

$\begin{matrix}{Q_{O\; 2} = \frac{{fV}_{T}\left( {F_{{IO}\; 2} - {.209}} \right)}{\beta\left( {F_{{DO}\; 2} - {.209}} \right)}} & (5)\end{matrix}$

When implemented to control an oxygen concentrator (oxygen deliverydevice) operating in a continuous flow mode, as determined at 1104(where a determination is made whether continuous or pulse mode is to beused), the device monitors oxygen purity (at 1134) and patientrespiration rate (at 1140) to compute and adjust the oxygen flow rate tobe delivered to the patient (at 1108). That is, the monitored values ofthe oxygen purity and patient respiration rate are provided (e.g., aspart of a feedback loop) to enable determination/adjustment of theoxygen flow rate.

When operating in a pulse flow mode, as determined at 1104, an oxygendelivery device provides a bolus of oxygen each time a patient breath isdetected (it should be noted that in some embodiments selection of flowmode or pulse mode may be performed manually based on input by a user,or it may be performed automatically based on detected conditions, suchas a condition where no breathing is detected for a period of time, aswas described in relation to FIG. 12). This bolus of oxygen combineswith the additional oxygen contained in the inspired breath of air toelevate the patient's FiO2. Since a pulse mode oxygen delivery device isdealing with a discrete volume of gas as opposed to a flow, the totalvolume of gas inhaled by a patient during each breath is the tidalvolume, V_(T). Tidal volume is the sum of the bolus volume of gas fromthe supplemental source, V_(O2), and the volume of air, V_(Air), asdescribed by Equation (6).V _(T) =V _(O2) +V _(Air)  (6)

Again, considering just the portion of these flows that are composed ofoxygen, Equation (7) follows where F_(IO2) is the fraction of oxygeninspired by the patient, F_(DO2), is the fraction of gas delivered bythe supplemental device that is composed of oxygen, and 0.209 representsthe fraction of oxygen found in normal atmospheric composition.F _(IO2) V _(T) =F _(DO2) V _(O2)+0.209V _(Air)  (7)

Equations (6) and (7) may be combined algebraically to derive equation(8). Equation (8) may be used to perform the “Calculate oxygen bolussize” operation at 1110 in the example procedure 1100 shown in FIG. 18.

$\begin{matrix}{V_{O\; 2} = \frac{V_{T}\left( {F_{{IO}\; 2} - {.209}} \right)}{\left( {F_{{DO}\; 2} - {.209}} \right)}} & (8)\end{matrix}$

The amount of oxygen that the oxygen delivery device has to produce,Q_(O2), when operating in pulse mode is the product of the volume of theboluses delivered V_(O2) and the patient's detected respiratory rate f(e.g., detected at 1140).

The advantage of controlling the operation of an oxygen delivery deviceto a specified fraction of inspired oxygen level is that it serves tobetter maintain the patient's blood oxygen saturation at appropriatetherapeutic levels while at the same time managing the amount of oxygendelivered to the patient. This is important when the oxygen deliverydevice is portable and battery operated. For such systems, the durationand weight of the system is a function that is affected by therespective battery capacity when the oxygen delivery device is aconcentrator or tank capacity when the oxygen delivery device utilizes aliquid oxygen storage vessel or high pressure gas cylinder for theoxygen source. Smaller batteries or cylinders/tanks allow for lighterand more convenient portable systems, but larger batteries andcylinders/tanks allow for longer operating durations. By controlling toa prescribed FiO2, a patient receives more oxygen when his/herrespiratory rate increases, such as during periods of exertion. As aresult, the patient's blood oxygen saturation remains at therapeuticallyappropriate levels and the patient feels better and is less likely toexperience an exacerbation of their respiratory condition. Conversely,when the patient's respiratory rate decreases, such as during periods ofrest or sleep, oxygen product rates from the device are reduced and thedevice can operate longer.

In addition, the methods and apparatus for controlling an oxygendelivery device to a specified FiO2 may be combined with otherprocedures/methods for controlling an oxygen delivery device to furtheroptimize device operation and dimensions. Such other methods/proceduresinclude, but are not limited to: a) oxygen purity feedback, determinedat 1134 by, for example, an oxygen purity sensor, b) system pressurefeedback, determined at 1132 by, for example, a pressure sensor, and c)temperature compensation based on measured temperature determined at1116 by, for example, a thermistor, which is then used to adjust, at1114, the computed flow rate or bolus size. Other factors and proceduresthat effect delivery of oxygen to a patient may be combined into aprocedure such as the procedure 1100 of FIG. 18. Computed flow rates orbolus sizes may then be provided to a controller, or variouscontrollers, configured to control operation of the oxygen deliverydevice and thus the flow of oxygen (at 1142) to the patient. Forexample, the computed flow rate may be provided to a motor controller(at 1120) which in turn causes controlled actuation of the motor (at1124) that drives the oxygen delivery device's compressor (at 1126). Thecomputed flow rate is also used to control the valve speed in theoperation of the oxygen delivery module (at 1128)]

The main elements of embodiments of the oxygen device 100 have beendescribed above. FIG. 30 is a schematic flow diagram to furtherillustrate the configuration and operations of an oxygen deliverydevice.

The following sections describe a number of additional features, one ormore of which may be incorporated into the embodiments of the oxygendelivery device described herein.

II. Conserving Device

With reference to FIG. 19, a conserving device or demand device 190 maybe incorporated into the system 100 to more efficiently utilize theoxygen produced by the oxygen gas generator 102. During normalrespiration, a user 108 inhales for about one-third of the time of theinhale/exhale cycle and exhales the other two-thirds of the time. Anyoxygen flow provided to the user 108 during exhalation is of no use tothe user 108 and, consequently, the additional battery power used toeffectively provide this extra oxygen flow is wasted. A conservingdevice 190 may include a sensor that senses the inhale/exhale cycle bysensing pressure changes in the cannula 111 or another part of thesystem 100, and supply oxygen only during the inhale portion or afraction of the inhale portion of the breathing cycle. For example,because the last bit of air inhaled is of no particular use because itis trapped between the nose and the top of the lungs, the conservingdevice 190 may be configured to stop oxygen flow prior to the end ofinhalation, improving the efficiency of the system 100. Improvedefficiency translates into a reduction in the size, weight, cost andpower requirements of the system 100.

The conserving device 190 may be a stand-alone device in the output lineof the system 100, similar to a regulator for scuba diving, or may becoupled to the control unit 110 for controlling the oxygen generator 102to supply oxygen only during inhalation by the user 108.

The conserving device 190 may include one or more sensors, such as thesensors described above. For example, the conserving device may includea sensor for monitoring the respiration rate of the user.

In some embodiments, the conserving device may include a supply valvesuch as the supply valve 160 described above. In some embodiments, avalve implementation for supply valve 160 shown in FIG. 1B may be apiezoelectric (“piezo”) valve. For instance, although in someembodiments, one or more of the valves may be a proportional solenoidvalve for controlling the flow of gas to be provided to a subject, suchas when operating in a conservation or pulse mode, in some embodiments,one or more valves may be based upon using a piezo element which may beemployed for opening the valve. For example, a piezo valve may besubstituted for a solenoid valve so as to control the flow of the gas.The piezo valve connects electrically to a driver that in turn connectsto the control microprocessor and power bus. The use of a piezo valvemay be useful because it may respond faster to the controller than amore traditional solenoid valve. This in turn may result in a higherFiO2, and may better allow for the tailoring of the gas flow waveform soas to better treat the subject. The use of a piezo valve may also leadto lower power consumption and further cost savings because they arerelatively inexpensive to produce.

Accordingly, in some embodiments, an oxygen delivery device may beprovided that includes an oxygen delivery module (e.g., PSA, VPSA) toprovide at least concentrated oxygen, a piezoelectric valve coupled toan output of the oxygen delivery module to receive the producedconcentrated oxygen, a driver to electrically actuate the piezoelectricvalve, and a controller to control the driver to cause controllableactuation of the piezoelectric valve by the driver so as to causecontrollable opening of the valve to enable flow of oxygen delivered bythe oxygen delivery module to be directed for inhalation by a patientvia the piezoelectric valve. In some implementations, the oxygendelivery device may also include one or more sensors to determine datarepresentative of one or more of environmental conditions (e.g.,temperature, altitude), operating conditions of the oxygen deliverydevice (pressure, motor speed), and the patient's therapeutic conditions(e.g., level of activity). The controller may thus be to control thedriver to cause controllable actuation of the piezoelectric valve based,at least in part, on the determined data from the one or more sensorsrepresentative of the one or more of environmental conditions, operatingconditions of the oxygen delivery device, and patient's therapeuticconditions.

With reference to FIG. 20, a flow chart of an example procedure 1200 tocontrol oxygen delivery is shown. The procedure 1200 includesdetermining 1210 data representative of one or more of environmentalconditions, operating conditions of an oxygen delivery device, and apatient's therapeutic conditions. Based, at least in part, on thedetermined data from the one or more sensors representative of the oneor more of the environmental conditions, the operating conditions of theoxygen delivery device, and the patient's therapeutic conditions, adriver actuating a piezoelectric valve coupled to an output of an oxygendelivery module of an oxygen delivery device is controlled 1220 to causecontrollable opening of the valve to enable flow of oxygen delivered bythe oxygen delivery module to be directed for inhalation by the patientvia the piezoelectric valve.

The system 100 (as depicted in FIG. 19) may also include a specialcannula retraction device for retracting the cannula 111 when not inuse. Further, the cannula 111 may come in different lengths and sizes.

III. Tracking Device

With reference back to FIGS. 1B and 14, in some embodiments, the system100 may include a global positioning system (GPS) receiver 192 fordetermining the location of the system 100. The location of the receiver192 and, hence, the user 108 can be transmitted to a remote computer viathe communication module (telemetry mechanism or modem). This may enablelocating the user 108 in the event the user has a health problem, e.g.,heart attack, when the user hits a panic button on the system, when analarm is activated on the system, or for some other reason.

Thus, because a concentrator may not returned to the equipment providerwhen a patient goes off therapy, a mechanism (e.g., implemented on aprocessor-based device using software) may be included so as to trackthe physical position of the concentrator. A locator, therefore, may beprovided in association with the concentrator. For instance, a GPSdevice may be included in combination with a cellular network so as tolocate the device. Alternatively, a WiFi enabled geolocator may beprovided. In one embodiment, a WiFi transmitter is provided such that ifthe device is near a WiFi hotspot, the hotspot will pick it up and thentransmit a signal, e.g., via the internet, to the equipment provider tothis inform the provider of the equipments location.

Further still, a small PC board could be built and mounted inside theconcentrator that would sound a buzzer at a given time period, e.g.,every 60 seconds, if the device has not been turned on in a definedperiod of time, e.g., six weeks. This will notify a person of thepresence of the device and its need for return, thus preventing loss ordelayed return of concentrator to the provider.

Thus, in some embodiments, an oxygen delivery device may be providedthat includes an oxygen delivery module (e.g., PSA, VPSA) to produce atleast concentrated oxygen, and a tracking device coupled to the oxygendelivery device to enable determining geographical location of theoxygen delivery device. The tracking device including one or more of,for example:

-   -   a) A WiFi-based geolocation device including a wireless receive        configured to determine availability of WiFi-based network        routers in the vicinity of the oxygen delivery device, and to        communicate with one or more of the WiFi-based network routers        available in the vicinity of the oxygen delivery device. An        approximation of the geographical location of the oxygen        delivery device is thus determined based on location data        associated with the one or more WiFi-based network routers        (whose geographical locations are generally known) communicating        with the oxygen delivery device.    -   b) A GPS-based tracking device to receive GPS signals from one        or more satellite, determine approximate position of the        GPS-tracking device based on the received GPS signals, and        communicate to a remote location data representative of the        determined the approximate position of the GPS-tracking device.    -   c) A device to monitor use of the oxygen delivery device, and to        cause an alarm to be activated in response to a determination        that the oxygen delivery device was not used for at least a        pre-determined period of time.

In some embodiments, additional functionality (e.g., through aprogrammable processor implementation) may be provided to allow forremote setup of the device. For example, when a concentrator includespulse mode operation, remote set up is useful to help ensure that thesubject is receiving adequate oxygen saturation. For example, using thesystem control and monitoring operations of the oxygen delivery device,and data from clinical sensors, the oxygen delivery device may beprogrammed and otherwise set up remotely. Specifically, a pulse oximetermay be provided and data derived from the pulse oximeter is transmittedback to the provider. The provider can then use that data to titrate thepatient and set up the device remotely. This will help serve subjects inremote areas or other areas where it is hard to access in personhealthcare services. This can also reduce the cost of patient setup atthe same time as increasing efficiency.

Accordingly, in some embodiments, an oxygen delivery device may beprovided that includes an oxygen delivery module to produce at leastconcentrated oxygen, and at least one sensor to determine datarepresentative of one or more of environmental conditions, operatingconditions of the oxygen delivery device, and patient's therapeuticconditions. The oxygen delivery device also includes a controllerconfigured to communicate the determined data to a remote station tofacilitate determining values of operation parameters controllingoperation of the oxygen delivery device based on, at least in part, thecommunicated data representative of the one or more of the environmentalconditions, the operating conditions of the oxygen delivery device, andthe patient's therapeutic conditions. The controller is furtherconfigured to receive from the remote station data representative of thevalues of the operation parameters controlling operation of the oxygendelivery device, and adjust the operation parameters of the oxygendelivery device based on the data received from the remote station.

With reference to FIG. 22, a flow chart of an example procedure 1250 toimplement remote set up is shown. The procedure 1250 includesdetermining 1260 data representative of one or more of environmentalconditions, operating conditions of an oxygen delivery device comprisingan oxygen delivery module to produce at least concentrated oxygen, andpatient's therapeutic conditions. The determined data representative ofthe one or more of the environmental conditions, the operatingconditions of the oxygen delivery device, and the patient's therapeuticcondition, is communicated 1270 to a remote station to facilitatedetermining values of operation parameters controlling operation of theoxygen delivery device. Subsequently, operation parameter datarepresentative of the values of the operation parameters to controloperation of the oxygen delivery device is received 1280 from the remotestation. The operation parameters of the oxygen delivery device areadjusted 1290 based on the data received from the remote station.

IV. Additional Operational Features and Accessories

In some embodiments, an oxygen delivery device, such as a portableoxygen delivery device described herein, may additionally be used withnebulizers for the delivery of aerosolized medications. For instance, anebulizer may be included so as to receive and convert a medication into a mist that may then be added into the oxygen flow so as to deliverthe mist into the lungs with the inhalation of the oxygen beingdelivered. Such embodiments can be employed with the appropriatemedication so as to treat any disease capable of being treated withnebulized medicaments, such as cystic fibrosis, asthma, and otherrespiratory diseases. Any suitable nebulizer may be employed so long asit is capable of being integrated into the concentrator system, such asa jet nebulizer and/or atomizer. For example, the nebulizer, e.g., a jetnebulizer, may be connected via tubing to the concentrator, wherein theoxygen delivered to the nebulizer blasts at high velocity through theliquid medicine converting it into an aerosol, which is then deliveredand inhaled by the subject. Hence, the continuous flow gas stream comingfrom the concentrator may be configured to function as the gas sourcefor a nebulizer.

Thus, and with reference to FIG. 21, in some embodiments, a respiratorydevice 1900 is provided that includes an oxygen delivery deviceincluding an oxygen delivery module to produce at least concentratedoxygen, and a gas moving device to deliver air to the oxygen deliverymodule (not shown in FIG. 21), with the gas moving device being drivenby a motor (not shown in FIG. 21) to actuate the gas moving device. Therespiratory device also includes a nebulizer containing liquidmedication 1930 for a patient that is stored in a medication chamber (orreservoir) 1910 defined within the nebulizer, the nebulizer beingcoupled to the oxygen delivery device such that the concentrated oxygenproduced by the oxygen delivery module is directed (e.g., via a tube1920) into the inner medication chamber 1910 of the nebulizer to convertat least some of the liquid medication 1930 into aerosol medication1940. At least some of the concentrated oxygen directed into thenebulizer and the at least some of the converted aerosol medication aredelivered for inhalation by a patient through a nebulizer outlet port.

With reference to FIG. 23, a flow chart of an example embodiment of aprocedure 1300 to deliver aerosolized medications is shown. Theprocedure 1300 includes producing 1310 concentrated oxygen using anoxygen delivery device including an oxygen delivery module (e.g., PSA,VPSA) to produce at least the concentrated oxygen, and a gas movingdevice (e.g., a compressor) to deliver air to the oxygen deliverymodule. At least some of liquid medication (e.g., to treat cysticfibrosis, asthma, and/or other respiratory diseases) contained in amedication chamber of a nebulizer is converted 1320 into aerosolmedication by directing the concentrated oxygen produced by the oxygendelivery module into the nebulizer. As noted, in some embodiments, thenebulizer may include a jet nebulizer configured to use the concentratedoxygen directed into the nebulizer at high velocity as a gas source tocause the liquid medication to be converted to aerosol. At least some ofthe concentrated oxygen directed into the nebulizer and at least some ofthe converted aerosol medication for inhalation by a patient isdelivered 1330 through a nebulizer outlet port.

In some embodiments, in a similar manner, when the concentrator isoperating in a continuous flow mode, the gas from the concentrator maybe fed into a closed container holding a scented fluid. When fed througha conduit and/or diffuser into the bottom of the container, the gas willbubble up through the fluid, entraining an amount of fluid vapor withit. An outlet at the top of the container will allow the egress of thegas with the entrained vapor into a connection leading to the subject.In a manner such as this, patient compliance with oxygen therapy may beencouraged and/or respiratory disinfection, decongestion, expectorationor beneficial psychological effects may be achieved. It is to be notedthat water may be substituted herein for the scented fluid, thus servingas a humidifier and functioning to add a water vapor into the oxygenbeing delivered to the subject.

Accordingly, in some implementations, an oxygen delivery device isprovided that includes an oxygen delivery device including an oxygendelivery module (e.g., PSA, VPSA) to produce at least concentratedoxygen, and a gas moving device (e.g., a compressor) to deliver air tothe oxygen delivery module. The gas moving device is driven by a motorto actuate the gas moving device. The oxygen delivery device alsoincludes a container holding fluid, the container being coupled to theoxygen delivery device such that the concentrated oxygen produced by theoxygen delivery module is directed into the container to be passedthrough the fluid so as to entrain at least some fluid vapor. At leastsome of the concentrated oxygen directed into the container and thefluid vapor are delivered for inhalation by a patient through an outletof the container.

With reference to FIG. 24, a flow chart of an example embodimentprocedure 1350 to deliver fluid vapor is shown. The procedure 1350includes producing 1360 concentrated oxygen using an oxygen deliverydevice including an oxygen delivery module to produce at least theconcentrated oxygen, and a gas moving device to deliver ambient air tothe oxygen delivery module. The concentrated oxygen is directed 1370through fluid in a container to entrain at least some of fluid intofluid vapor. In some embodiments, the fluid may include water and/orscented fluid. At least some of the concentrated oxygen directed intothe fluid container and the entrained fluid vapor for inhalation by apatient is delivered 1380 through an outlet of the container.

As noted above, patient compliance with a prescribed therapeuticdelivery of oxygen is important. Accordingly, the systems and devicesdescribed herein may be configured for monitoring one or more of hoursof usage, times of usage, flow rates, respiration rates, and the like soas to track and/or send, e.g., to a healthcare professional, a subject'scompliance. The concentrator may also be configured so as to monitorother parameters as well, such as a biometric patient identifier, sleepstate, exercise rate, heart rate, level of ambulation, SpO2, and thelike. Such data may then be analyzed and/or compiled to form a morecomplete picture of the subject's compliance, and therapy effectiveness.

Thus, in some implementations, an oxygen delivery device is providedthat includes an oxygen delivery module (e.g., PSA, VPSA), one or moresensors to determine data representative of one or more of environmentalconditions, operating conditions of the oxygen delivery device, andpatient's characteristics, and a controller to control, based at leastin part on the determined data, at least the oxygen delivery module'soperations. The oxygen delivery device also includes an identificationmodule to receive information representative of an identity of a userand to compare the received information to stored data uniquelyidentifying a patient associated with the portable oxygen deliverydevice, and a display module to present information based, at least inpart, on data determined by the one or more sensors. The controller maythus associate patient identification with data collected by the one ormore sensors. The information displayed may include trends of theavailable information. Data collected/determined by the one or moresensors may be used to compute one or more of, for example, sleep state,respiratory rate, inspiratory:expiratory time ratio, ambulation time,activity level, oxygen saturation, total oxygen delivered, heart rate,oxygen delivered per period of time, hours of usage, and/or usage time.The display device may be configured to present information based, atleast in part, on the data determined by the one or more sensors inresponse to a determination by the identification module that the datadetermined by the one or more sensor corresponds to the patientidentified by the identification module.

In some embodiments, the one or more sensors may include, for example anelectroencephalogram, an electrooculogram, an electrocardiogram, anactigraph, a pedometer, a pulse oximeter, an accelerometer, a pressuresensor, a flow sensor, a purity sensor, a clock, and/or a timer. In someembodiments, the identification module may include one or more of, forexample, an alpha-numeric keypad, an iris scanner, a magnetic stripecard, a barcode scanner, a fingerprint scanner, a facial featurerecognition device, and a palm scanner.

In some embodiments, the controller may further be configured to comparethe determined data representative of the one or more of theenvironmental conditions, the operating conditions of the oxygendelivery device, and the patient's characteristics, to respectivepre-determined threshold values representative of one or more of normalenvironmental conditions, normal operating conditions of the oxygendelivery device, and normal patient's characteristics, and communicatean alert in response to a determination that at least one of thedetermined data representative of the one or more of the environmentalconditions, the operating conditions of the oxygen delivery device, andthe patient's characteristics, deviates from a respective at least oneof the pre-determined threshold values representative of one or more ofnormal environmental conditions, normal operating conditions of theoxygen delivery device, and normal patient's characteristics.

For instance, in some embodiments, the concentrator may be configured todetect and/or monitor a subject's respiratory rate, such as while thepatient is ambulatory or sleeping. For example BPM data, e.g., while theconcentrator is delivering at a constant flow, may be extracted and thedata communicated to the controller. In one instance, a pressure sensormay be fluidly attached to the lumen of a cannula, which sensor candetect pressure and thus be used to determine actual BPM and therebymonitor the subject's respiratory rate.

In some embodiments, identity of the patient may be determined using abiometric patient identifier may be determined, for instance, byemploying the same features used to sense and index unique physiologicalinformation, such as iris scan, palm scan, finger print, facial featurerecognition, and the like. A sleep state may also be determined. Forexample, a sensor, such as a sensor conventionally used inpolysomography (electroencephalogram (EEG), electrooculogram (EOG),electrocardiogram (ECG)), and the like may be used, or alternately anactigraph or ZEO® sleep system technology may be employed in combinationwith a oxygen delivery device of the disclosure so as to determine asubject's sleep state. A level of ambulation may also be determined soas to measure how active a subject is during a given period of time.This can be done with an actigraph, pedometer, and the like for use incombination with an oxygen delivery device of the disclosure. Any ofthis information may then be communicated to the controller of theconcentrator, e.g., via wire or wirelessly, and employed to ensure thatat least a minimum selected amount of oxygen and a minimum selectedpurity level is maintained given the measured changing needs of thesubject. Such information can additionally serve to increase subjectcompliance which should in turn decrease COPD recidivision, decreaseinsurance fraud, and better provide usage data which would in turn beused to design better products.

Further, in some embodiments, the oxygen delivery device may include adisplay for displaying one or more sensed data and the like. Forinstance, a display may be used to indicate data pertinent to acharacteristic of the device and/or a characteristic of a subject, suchas a subject's need for oxygen. For instance, the display may display arate of flow, a purity level of oxygen in the flow, ambient temperatureor altitude, moisture level, battery life remaining, usage data, and thelike. Further, the display may indicate a measured parameter such asubject's oxygenation level, blood pressure, peripheral oxygensaturation (SpO2) level, breaths per minute (BPM), as well as agraphical representation showing a given trend for one or more of theabove, and the like.

Such a display would be useful because while a subject may subjectivelybelieve that there are no problematic issues as regards the use of theconcentrator to provide supplemental oxygen, their breathing rate BPMmay increase during exertion or their peripheral oxygen saturation(SpO2) could decrease below a particular level deemed safe, e.g., below90%, for various reasons, including exertion, insufficient delivery ofoxygen, malfunctioning of one or more components of the concentrator,improper cannula use, and the like. The visual display may be useful soas to ensure the user that all is functioning well and/or to warn theuser when all is not functioning well, and/or to provide the user withtrending data will allow a user or caregiver to correlate actions withthese biological indicators of health status. The display, therefore,can serve to indicate and/or alert the subject and/or a caregiver to thesubject's health status.

Accordingly, in some embodiments, an oxygen delivery device is providedthat includes an oxygen delivery module (e.g., a PSA, VPSA, a liquidoxygen storage system, a high pressure gaseous oxygen storage system, acompressing mechanism to compress oxygen-rich gas to a higher pressure),and one or more sensors to determine data representative of one or moreof environmental conditions, operating conditions of the oxygen deliverydevice, and patient's characteristics. As noted, such sensors mayinclude one or more of, for example, an electroencephalogram, anelectrooculogram, an electrocardiogram, an actigraph, a pedometer, apulse oximeter, an accelerometer, a pressure sensor, a flow sensor, apurity sensor, a clock, and/or a timer. The oxygen delivery devicefurther includes a controller to control, based at least in part on thedetermined data, at least the oxygen delivery module's operations, andalso includes a display module (e.g., a module using a CRT screen, a LCDscreen, a plasma screen, etc.) to present information based, at least inpart, on the data representative of the characteristics of the patient.Such a display module may also be configured as a user input interface,e.g., a touch screen. The display module may also include discretebuttons adjacent, or otherwise proximate to, the display area to enableproviding user input. The information presented on the display modulemay include one or more of, for example, patient's sleep state,patient's respiratory rate, inspiratory:expiratory time ratio,ambulation time, activity level, oxygen saturation, total oxygendelivered, heart rate, oxygen delivered per period of time, hours ofusage, and/or usage time, and may further include information pertainingto trends of the available information. The oxygen delivery device mayalso include a communication module to communicate data to a remotelocation using one or more of, for example, a wireless communicationlink, and a wired-based communication link.

In some embodiments, an accessory to measure and display thestate-of-charge and state-of-life for the battery 104 of an oxygendelivery device would be utilized. Such a device may be a separateaccessory (either hand-held or table-top) to enable an user to readilydetermine the state-of-charge of the battery pack (for proper storageand/or shipping) and also the present state-of-life of the pack (i.e.number of remaining full charge/discharge cycles before the pack reaches80% of its original ‘when new’ capacity). A table-top version of thisdevice could also have an added feature to enable providers to easilycharge packs in their storage inventory to an optimum charge condition(e.g. a 40% charged state) to ensure maximum life of the packs. Suchfunctionality to measure and display the state-of-charge andstate-of-life for a battery could also be incorporated into the userinterface of an oxygen delivery device.

In some embodiments, the controller, such as the controller 110depicted, for example, in FIG. 1A, may be configured with a factorydefault mode, which functions to return the device to its factorydefault settings. This can simplify service, refurbishment betweenpatients, and minimize troubleshooting time. Accordingly, in someimplementations, an oxygen delivery device is provided that includes acontroller to control at least some operations of the oxygen deliverydevice, including controlling operations affecting the oxygen deliverymodule, that includes at least one processor based device, and at leastone non-transitory memory storage device to store computer instructions.The computer instructions include instructions that when executed on theat least one processor-based device cause the at least oneprocessor-based device to receive data indicative that defaultoperational settings of the oxygen delivery device are to be activated,and, in response to the received data, activate the default operationalsettings of the oxygen delivery device.

Additionally, the controller's configuration (e.g., implemented byprogramming a controller that includes a programmable processor-baseddevice) may be configured with a limp home mode. In such a mode, ratherthan merely showing a malfunction of other error state where oxygenproduction is stopped, the device is programmed to operate so long as itcan make some amount of oxygen greater than a given minimal purity,e.g., greater than 21% purity, and deliver it to a subject. In thismanner, a subject who would otherwise not get oxygen because the devicehas shut down is still able to get some beneficial amount of oxygen.

Thus, in some implementations, an oxygen delivery device is providedthat includes an oxygen delivery module to produce at least concentratedoxygen, a purity sensor to determine oxygen purity value produced by theoxygen delivery module, and one or more device sensors to monitor theoperation of the oxygen delivery device. The oxygen delivery device alsoincludes a controller configured to receive data from the purity sensorand the one or more device sensors, to determine, based on the datareceived from the one or more device sensors, whether an operationalproblem condition exists in relation to the operation of the oxygendelivery device, and, in response to a determination that a problemcondition exists in relation to the operation of the oxygen deliverydevice, to cause at least partial operation of the oxygen deliverydevice to be maintained upon a further determination, based on the datareceived from the purity sensor, that the oxygen purity level exceeds apre-determined minimum purity threshold.

With reference to FIG. 25, a flow chart of an example embodiment of aprocedure 1400 to operate an oxygen delivery device is shown. Theprocedure includes receiving 1410 data from a purity sensorrepresentative of the oxygen purity level of oxygen produced by anoxygen delivery module of an oxygen delivery device, and receiving 1420data from one or more device sensors monitoring the operation of theoxygen delivery device. Based on the data received from the one or moredevice sensors, a determination is made 1430 of whether an operationalproblem condition exists in relation to the operation of the oxygendelivery device. In response to a determination that a problem conditionexists in relation to the operation of the oxygen delivery device, atleast partial operation of the oxygen delivery device is caused to bemaintained 1440 upon a further determination, based on the data receivedfrom the purity sensor, that the oxygen purity level exceeds apre-determined minimum purity threshold. In some embodiments. thepre-determined minimum purity threshold is 21%. In some embodiments, thecontroller is configured to cause a change from an operation mode thatwas active before the determination that a problem condition exists toanother operational mode for the oxygen delivery device.

A lockout mode may also be provided, thus enabling or disabling one ormore given modes of operation. Accordingly, in some implementations, anoxygen delivery device may be provided that includes an oxygen deliverymodule to produce at least concentrated oxygen, a controller to controlat least some operations of the oxygen delivery device, includingcontrolling operation affecting operations of the oxygen deliverymodule, the controller configured to enable the activation of one ormore of a plurality of operational modes supported by the oxygendelivery device. The controller includes at least one processor baseddevice, and at least one non-transitory memory storage device to storecomputer instructions. The computer instructions include instructions tocause the at least one processor-based device to receive data indicativeof one or more operational modes from the plurality of operational modesthat are to be activated, and in response to the received data, enablethe one or more operational modes of the oxygen delivery device that areto be activated. Modes of operation that may be disabled include thosethat may not be therapeutically appropriate for a patient (i.e. pulsemode) or modes including advanced operating features. The instructionsmay also include instructions to cause the at least one processor-baseddevice to receive data indicative of at least one active operationalmode that is to be disabled. In some embodiments, the controller may beconfigured to cause the oxygen delivery device to operate in a defaultgeneric mode when all other of the plurality of operational modes arenot active.

In some embodiments, a method for preventing the use of counterfeit ornon-manufacturer approved battery packs may be provided. Battery packsrepresent a significant portion of the cost of oxygen delivery systemsand as such create the potential for users to want to utilize lower costbattery packs. Such alternate battery packs may lack the correct safetyfeatures and hardware compatibility, which in turn could create a safetyhazard and loss of revenue for the manufacturer. While mechanical orelectrical methods may be readily reverse engineered, a software methodwith cryptographic function is more secure. Thus, within the batterypack 104 a battery management chip that utilizes a cryptographicfunction, such as SHA-1 (Secure Hash Algorithm) or some similarencryption procedure, may be used to identify an approved battery andnot allow operation of the oxygen delivery system with batteries thatare not approved by the original equipment manufacturer.

In some embodiments, a maintenance reminder light may also be providedso as to indicate when regular, periodic (or sensed) maintenance is notperformed. The indicator may be displayed to the user to alert them thatmaintenance needs to be performed. Thus, an oxygen delivery device maytherefore include a user interface including an indicator to indicatethat maintenance of the oxygen delivery device is required in responseto a determination of deviations from a maintenance schedule requiredfor the oxygen delivery device.

In some implementations, a controller, such as the controller 110 ofFIG. 1A, may be configured (e.g., by programming a programmableprocessor-based controller) for automated debugging, calibration, and ordiagnostics. Such configuration may reduce the service cost and timerequired for servicing an oxygen concentrator. Accordingly, in someembodiments, an oxygen delivery device is provided that includes anoxygen delivery module (e.g., PSA, VPSA, etc.) to produce at leastconcentrated oxygen, and a controller to perform one or more of, forexample, controlling at least some operations of the oxygen deliverydevice, identifying problems associated with the oxygen delivery device,resolving the identified problems associated with the oxygen deliverydevice, and/or calibrating the oxygen delivery device. The controllerincludes at least one processor based device, and at least onenon-transitory memory storage device to store computer instructions. Thecomputer instructions include instructions that when executed on the atleast one processor-based device cause the at least one processor-baseddevice to receive data representative of operation of the oxygendelivery device, and determine automatically problems associated withthe operations of the oxygen delivery device based on the received data.

In some embodiments, the computer instructions include instructions thatcause the processor-based device to determine automatically problemsassociated with the operations of the oxygen delivery device using anexpert system learning engine. In some embodiments, the computerinstructions include instructions that cause the processor-based deviceto automatically determine data to controllably change one or moreoperation parameters of the oxygen delivery device to cause a change inthe operation of the respiratory care device, and to change theoperation parameters of the oxygen delivery device according to thedetermined data. Further details regarding remote and/or automateddebugging, calibration and diagnostic are provided, for example, inpatent application Ser. No. 12/892,793, entitled “Controlling andCommunicating with Respiratory Care Devices,” the content of which ishereby incorporated by reference in its entirety.

In some embodiments, to speed factory or field calibration of the oxygenconcentrator, a tee fitting can be included upstream of the puritysensor. In this manner oxygen of a known purity can be directed throughthis tee when the concentrator is not producing oxygen and the sensormay be calibrated accordingly. For instance, by placing a tee fittingupstream of a purity sensor, a calibration gas of known composition canbe fed into the concentration sensor thereby allowing the sensor to becalibrated faster and with greater accuracy. When the sensor is notbeing calibrated, the port may be capped. Thus, in some embodiments, anoxygen delivery device may further include a purity sensor to determineoxygen purity value, a coupler (e.g., a tee-coupler) coupled to thepurity sensor, the coupler including an inlet port to receive gas froman external source. The oxygen delivery device includes a controllerconfigured to receive data from the purity sensor measuring the purityof oxygen delivered from an external oxygen source (the oxygen from theexternal oxygen source having a known oxygen purity level) and calibratethe purity sensor based on the purity value measured by the puritysensor for the oxygen having the known oxygen purity level deliveredfrom the external oxygen source

In some embodiments, the portable oxygen concentration system 100described herein may include additional programming, options andaccessories. For instance, some programmable features that may beimplemented (e.g., for programmable processor-based controllers) may beincluded for active sound cancellation. For example, a microphone andspeaker may be provided so as to communicate with the controller. Thecontroller may be programmed so as to create a phase-shifted or invertedsound source and thereby cancel out a portion of the sound created bythe concentrator. Specifically, since sound is a pressure waveconsisting of a compression phase and a rarefaction phase, anoise-cancellation speaker may be included and configured for emitting asound wave with the same amplitude but with an inverted phase (alsoknown as antiphase) to the original sound. Thus, when the waves combineto form a new wave (i.e., when they destructively interfere), they willeffectively cancel each other out, an effect which is called phasecancellation. The resulting sound wave may be so faint as to beinaudible to human ears. A noise-cancellation speaker may be co-locatedwith the sound source to be attenuated, e.g., concentrator compressor,and the speaker will have the same or similar audio power level as thecompressor and/or vacuum pump. In a manner such as this, the sound levelin the concentrator may be reduced. Since the compressor is the primarysource of low frequency sound which is difficult to attenuate withpassive means, active sound cancellation can be used to negate the lowfrequency sound, while passive means may be used to mitigate higherfrequencies. Accordingly, in some implementation, an oxygen deliverydevice may further include a sound system to generate acoustic signalsto cancel out at least some of the noise produced from operation of theoxygen delivery device. Such a sound system may be configured togenerate acoustic signals with a phase that is shifted or invertedrelative to at least some of the noise produced by operation of theoxygen delivery device, and may include a microphone to measure thenoise produced from operation of the oxygen delivery device, and acontroller (which may be different or the same as the controller 110 ofFIG. 1A) configured to determine characteristics of the noise measuredby the microphone, and to control the acoustic signals to be generatedby a speaker. In some embodiments, another mechanism to quiet oxygendelivery devices may include the provision of an appropriate switchingmechanism configured for shutting off the active cooling system of theconcentrator when it is not needed. For instance, during low temperatureoperation, or when the heat load of the device does not warrant its use,the active cooling system of the concentrator, e.g., a fan, is turnedoff or run at a lower speed, to thus conserve power and reduce the noiseof the overall system. Accordingly, in some implementations, an oxygendelivery device may further include a fan to cool the oxygen deliverydevice, at least one temperature sensor, and a controller to controloperation of the fan based on data representative of temperaturemeasured by the at least one temperature sensor. The controller isconfigured to cause one of, for example, terminating the operation ofthe fan and/or reducing speed of the fan upon a determination, based onthe data representative of the temperature, that the measuredtemperature is below a pre-determined temperature threshold.

Additionally, in some variations, a fan may be controlled to control thetemperature of a concentrator (e.g., ATF) to optimize system efficiency.Therefore, in some implementations, an oxygen delivery device may beprovided that includes an oxygen delivery module to produce at leastconcentrated oxygen, a gas moving device (e.g., a compressor) to deliverambient air to the oxygen delivery module, a fan to cool the oxygendelivery device, at least one temperature sensor, and one or moresensors to determine data representative of one or more of environmentalconditions, operating conditions of the oxygen delivery device, and apatient's therapeutic conditions. The device also includes a controllerto control operation of the fan based on the data determined by the oneor more sensors, including the temperature measured by the temperaturesensor, to control the fan to cause the temperature of the oxygendelivery device to be at an optimal temperature at which powerconsumption of the oxygen delivery device for a particular set ofperformance requirements is optimized. The controller may further beconfigured to determine the optimal temperature at which the powerconsumption of the oxygen delivery device for the particular set ofperformance requirements is optimized by, for example, varying fan speedin discrete steps over an interval of time, at each varied fan speedvalue determining the corresponding temperature and corresponding powerconsumption at the corresponding temperature, and identifying thetemperature that resulted in the minimal power consumption. In someembodiments, the particular set of performance requirements includes,for example, a particular oxygen purity level of oxygen produced by theoxygen delivery module, and/or a particular fraction of inspired oxygen(FiO2) value required for the patient.

A number of different types of bags and carrying cases such as, but notby way of limitation, a shoulder bag, a backpack, a fanny pack, a frontpack, and a split pack in different colors and patterns may be used totransport the system 100 and/or to transport other system accessories. Acover may be used to shield the system from inclement weather or otherenvironmental damage.

The system 100 may also be transported with a rolling trolley/cart, asuit case, or a travel case. The travel case may be adapted to carry thesystem 100 and may include enough room to carry the cannula 111, extrabatteries, an adapter, etc. Examples of hooks, straps, holders forholding the system 100 include, but not by way of limitation, hooks forseatbelts in cars, hooks/straps for walkers, hooks/straps, for wheelchairs, hooks/straps for hospital beds, hooks for other medical devicessuch as ventilators, hooks/straps for a golf bag or golf cart,hooks/straps for a bicycle, and a hanging hook.

For instance, in some embodiments, a cart may be provided in combinationwith the oxygen delivery device so as to increase the use and efficiencyof the system as a whole. For example, a pulse oximeter may be includedand positioned on the cart handle. In such a position, the oximeter canmonitor the patients SpO2 while the subject is handling the cart, forinstance, during exercising. Such a configuration therefore serves toalert the subject or a caregiver to the patient's health status. In someembodiments, a battery or AC power adapter may be positioned on thecart. For instance, portable oxygen concentrators are often kept onwheeled carts. Hence, the battery and/or the AC adapter can be mountedon the cart. The cart may also be configured for elevating theconcentrator to a level where the patient can comfortably reach controlson the concentrator. However, in certain embodiments, the features of acart, e.g., retractable/foldable handle and/or wheels may be integratedinto the enclosure of the actual concentrator such that the concentratorand cart make up one unit. The cart and/or concentrator may additionallybe configured to include a clock, timer, alarm, radio, MP3 player,cup-holder, and the like, for the convenience of a user.

Accordingly, in some embodiments, an oxygen delivery concentrator systemmay be provided that includes a cart, and an oxygen delivery deviceplaced on the cart. The oxygen delivery device includes an oxygendelivery module, at least one sensor to measure data representative ofat least one patient characteristic, the at least one sensor beingsecured to the cart (e.g., to the handle of the cart), and a controllerto receive the measured data and monitor the at least one patientcharacteristic based on the received measured data. In someimplementations, the cart may also be configured to elevate the oxygendelivery device to provide enhanced access by the patient to the oxygendelivery device. In some implementations, a battery pack and/or an ACadapter may also be mounted on the cart to facilitate transportation ofsuch a battery pack and/or an AC adapter. In some implementations, thecart may include a retractable/foldable handle, and may further includea base to receive a housing of the oxygen delivery device, the housingincluding integrated wheels such that when the housing with theintegrated wheels is received on the base of the cart, the wheels of thehousing are used to enable mobility of the cart. In someimplementations, the oxygen delivery device may include one or more of,for example, a clock, a radio, an ashtray, and/or a cup-holder.

With reference to FIG. 26, a flow chart of an example embodiment of aprocedure 1450 to operate an oxygen delivery device is shown. Theprocedure 1450 includes measuring 1460 data representative of at leastpatient characteristic using at least one sensor secured to a cart onwhich an oxygen delivery device is placed. In some embodiments, the atleast one sensor is secured to a handle of the cart such that the atleast one sensor is configured to measure the data representative of theat least one patient characteristic while the patient is grasping thehandle. The at least one sensor may include one or more of, for example,an oximeter to measure the patient's SpO2 level, and/or a pedometer tomeasure the patient's activity level. The measured data representativeof the at least one patient characteristic is received 1470 (e.g., by acontroller), and the at least one patient characteristic is monitored1480 based on the received measured data. In some implementations, theprocedure optionally also includes comparing the measured datarepresentative of the at least one patient characteristic to arespective at least one pre-determined threshold value representative ofnormal values for the corresponding at least one patient characteristic,and communicating an alert in response to a determination that themeasured data representative of the at least one patient characteristicdeviates from the respective at least one pre-determined threshold valuerepresentative of the normal values corresponding at least one patientcharacteristic.

The system 100 may also include one or more alarm options. An alarm ofthe system 100 may be actuated if, for example, a sensed physiologicalcondition of the user 108 falls outside a pre-defined range. Further,the alarm may include a panic alarm that may be manually activated bythe user 108. The alarm may actuate a buzzer or other sounding device onthe system 100 and/or cause a communication to be sent via acommunication module (telemetry mechanism or modem) to another entity,e.g., a doctor, a 911 dispatcher, a caregiver, a family member, etc.

In some embodiments, an oxygen concentration (O2) feed back control maybe provided in an oxygen concentrator device and may be configured(e.g., through software for use with a programmable-based controller) tocontrol the output O2 so as to maintain it in a given range (forexample: O2=90%+/−1%). This will allow the battery to run for a longerperiod of time and to improve the device control performance (in someimplementations, the oxygen delivery device may be controlled tomaintain the oxygen purity level at below 90%). Thus, in suchimplementations, an oxygen delivery device is provided that includes anoxygen delivery module to produce at least concentrated oxygen, a gasmoving device (e.g., a compressor) to deliver air to an oxygen deliverymodule, with the gas moving device being driven by a motor to actuatethe gas moving device. Such a device also includes a purity sensor todetermine oxygen purity value produced by the oxygen delivery module,and a controller to control operations of at least the oxygen deliverymodule and the gas moving device, based at least in part on thedetermined oxygen purity value, to cause the purity level of the oxygenproduced by the oxygen delivery module to be, for example, less than90%.

With reference to FIG. 27A, a diagram of an example embodiment of an O2control main flow 1500, implemented using, for example, a PID controller1510, is shown. The desired O2 Setting can be a fixed value or avariable value. If it is a variable, then, in some embodiments, whenexternal AC power is connected to a device, this setting can be, forinstance, 91% or higher. When the device is using a battery, the settingcan be lower, for example, it can be set up to 89% or lower, but not solow that the device triggers O2 Low Alarm. This setting can be changedthrough a user Interface.

FIG. 27B is a flow chart of an example procedure 1550 to control anoxygen delivery device. More particularly, the flow chart of FIG. 27Bshows the O2 control logic for compressor control. For ATF control,similar logic may be used. The flow chart shows the P (proportional), I(Integral) and D (derivative) computations. For some applications, onlyPI parts are used, and for some applications only the P part is used,e.g., for some simple applications. The proportional factor(PROPORTIONAL FACT), derivative factor (DERIVATIVE FACT), and integralfactor (INTEGRAL FACT) may be constants that can be determined duringPID tuning. In some embodiments, the Integral Timer is about 2 minutesor longer, depending on the concentrator control speed. A furtherembodiment of a procedure to control an oxygen delivery device (e.g.,controlling the oxygen purity produced by the device, and the air flowpressure) is provided in FIG. 31.

FIG. 28 is a block diagram illustrating an example computer system 1600that may be used to implement the various computing and processor-baseddevices described herein. For example, the computer system 1600 may beused to implement the controller 110 of the device 100, any of thesensors 108, any remote computing devices communicating with the device100, etc. However, other computer systems and/or architectures may beused.

The computer system 1600 includes, in some implementations, one or moreprocessors, such as processor 1602. Additional processors may beprovided, such as an auxiliary processor to manage input/output, anauxiliary processor to perform floating point mathematical operations, aspecial-purpose microprocessor having an architecture suitable for fastexecution of signal processing procedure (e.g., digital signalprocessor), a slave processor subordinate to the main processing system(e.g., back-end processor), an additional microprocessor or controllerfor dual or multiple processor systems, or a coprocessor. Such auxiliaryprocessors may be discrete processors or may be integrated with theprocessor 1602.

The processor 1602 may be connected to a communication bus 1604. Thecommunication bus 1604 may include a data channel for facilitatinginformation transfer between storage and other peripheral components ofthe computer system 1600. The communication bus 1604 further may providea set of signals used for communication with the processor 1602,including a data bus, address bus, and control bus (not shown). Thecommunication bus 1604 may comprise any standard or non-standard busarchitecture such as, for example, bus architectures compliant withindustry standard architecture (“ISA”), extended industry standardarchitecture (“EISA”), Micro Channel Architecture (“MCA”), peripheralcomponent interconnect (“PCI”) local bus, or standards promulgated bythe Institute of Electrical and Electronics Engineers (“IEEE”) includingIEEE 488 general-purpose interface bus (“GPIB”), IEEE 696/S-100, and thelike.

Computer system 1600 may also include a main memory 1606 and may alsoinclude a secondary memory 1608. The main memory 1606 provides storageof instructions and data for programs executing on the processor 1602.The main memory 1606 is typically semiconductor-based memory such asdynamic random access memory (“DRAM”) and/or static random access memory(“SRAM”). Other semiconductor-based memory types include, for example,synchronous dynamic random access memory (“SDRAM”), Ramous dynamicrandom access memory (“RDRAM”), ferroelectric random access memory(“FRAM”), and the like, including read only memory (“ROM”).

The secondary memory 1608 may optionally include a hard disk drive 1610and/or a removable storage drive 1612, for example a floppy disk drive,a magnetic tape drive, a compact disc (“CD”) drive, a digital versatiledisc (“DVD”) drive, etc. The removable storage drive 1612 reads fromand/or writes to a removable storage medium 1614. Removable storagemedium 1614 may be, for example, a floppy disk, magnetic tape, CD, DVD,etc.

The removable storage medium 1614 may be a non-transitory computerreadable medium having stored thereon computer executable code (e.g.,software) and/or data. Executable code may include computer executablecode to perform any of the procedures described herein. The computersoftware or data stored on the removable storage medium 1614 is readinto the computer system 1600 as electrical communication signals 1628.

In alternative embodiments, secondary memory 1608 may include othersimilar implementations for enabling computer programs or other data orinstructions to be loaded into the computer system 1600. Suchimplementations may include, for example, an external storage medium1622 and an interface 1620. Examples of external storage medium 1622 mayinclude an external hard disk drive or an external optical drive, or andexternal magneto-optical drive.

Other examples of secondary memory 1608 may include semiconductor-basedmemory such as programmable read-only memory (“PROM”), erasableprogrammable read-only memory (“EPROM”), electrically erasable read-onlymemory (“EEPROM”), or flash memory (block oriented memory similar toEEPROM). Also included are any other removable storage units 1622 andinterfaces 1620, which allow software and data to be transferred fromthe removable storage unit 1622 to the computer system 1600.

Computer system 1600 may also include a communication interface 1624.The communication interface 1624 allows software and data to betransferred between computer system 1600 and external devices (e.g.printers), networks, or information sources. For example, computersoftware or executable code may be transferred to computer system 1600from a network server via communication interface 1624. Examples ofcommunication interface 1624 include a modem, a network interface card(“NIC”), a communications port, a PCMCIA slot and card, an infraredinterface, and an IEEE 1394 fire-wire, just to name a few, which enablewire-based or wireless communication.

Communication interface 1624 may implement industry promulgated protocolstandards, such as Ethernet IEEE 802 standards, Fiber Channel, digitalsubscriber line (“DSL”), asynchronous digital subscriber line (“ADSL”),frame relay, asynchronous transfer mode (“ATM”), integrated digitalservices network (“ISDN”), personal communications services (“PCS”),transmission control protocol/Internet protocol (“TCP/IP”), serial lineInternet protocol/point to point protocol (“SLIP/PPP”), and so on, butmay also implement customized or non-standard interface protocols aswell.

Software and data transferred via communication interface 1624 aregenerally in the form of electrical communication signals 1628. Thesesignals 1628 may be provided to communication interface 1624 via acommunication channel 1626. Communication channel 1626 carries signals1628 and can be implemented using a variety of wired or wirelesscommunication means including wire or cable, fiber optics, conventionalphone line, cellular phone link, wireless data communication link, radiofrequency (“RE”) link, or infrared link, just to name a few.

Computer executable code (i.e., computer programs or software) may bestored in the main memory 1606 and/or the secondary memory 1608.Computer programs can also be received via communication interface 1624and stored in the main memory 1606 and/or the secondary memory 1608.Such computer programs, when executed, enable the computer system 1600to perform the various functions described herein.

In this disclosure, the term “computer readable medium” is used to referto any non-transitory media used to provide computer executable code(e.g., software and computer programs) to the computer system 1600.Examples of these media include main memory 1606, secondary memory 1608(including hard disk drive 560, removable storage medium 1614, andexternal storage medium 1622), and any peripheral device communicativelycoupled with communication interface 1624 (including a networkinformation server or other network device). These computer readablemedia are means for providing executable code, programming instructions,and software to the computer system 1600.

In embodiments that are implemented using software, the software may bestored on a computer readable medium and loaded into computer system1600 by way of removable storage drive 1612, interface 1620, orcommunication interface 1624. In such embodiments, the software isloaded into the computer system 1600 in the form of electricalcommunication signals 1628. The software, when executed by the processor1602, causes the processor 1602 to perform the features and functionsdescribed herein.

Various embodiments may also be implemented primarily in hardware using,for example, components such as application specific integrated circuits(“ASICs”), or field programmable gate arrays (“FPGAs”). Implementationof a hardware state machine capable of performing the functionsdescribed herein may also be used. Various embodiments may also beimplemented using a combination of both hardware and software.

The various illustrative logical blocks, modules, circuits, and methodsdescribed in connection with the above described figures and theembodiments disclosed herein can often be implemented as electronichardware, computer software, or combinations of both.

Moreover, the various illustrative logical blocks, modules, and methodsdescribed in connection with the embodiments disclosed herein can beimplemented or performed with a general purpose processor, a digitalsignal processor (“DSP”), an ASIC, FPGA or other programmable logicdevice, discrete gate or transistor logic, discrete hardware components,or any combination thereof designed to perform the functions describedherein. A general-purpose processor can be a microprocessor, but in thealternative, the processor can be any processor, controller,microcontroller, or state machine. A processor can also be implementedas a combination of computing devices, for example, a combination of aDSP and a microprocessor, a plurality of microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration.

Additionally, the methods/procedures described in connection with theembodiments disclosed herein can be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module can reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium including a network storagemedium. An exemplary storage medium can be coupled to the processor suchthat the processor can read information from, and write information to,the storage medium. In the alternative, the storage medium can beintegral to the processor. The processor and the storage medium can alsoreside in an ASIC.

A number of implementations of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.Accordingly, other embodiments are within the scope of the followingclaims.

What is claimed is:
 1. An oxygen delivery device comprising: an oxygendelivery module configured to receive compressed air from a compressorcomprising a piston having a single rotor configured to orbit aroundfirst eccentric on a shaft to compress ambient air into the compressedair, the oxygen deliver module comprising a rotary valve assembly thatrotates with respect to a plurality of adsorption beds to selectivelytransfer fluids through the plurality of adsorption beds in order toseparate concentrated oxygen and other gases within the compressed air,the compressor configured to be combined with a vacuum pump comprisinganother piston having a single rotor configured to orbit around a secondeccentric on the shaft to vacuum out the other gases, the compressor andthe vacuum being separated by an endplate that excludes one or moremotors driving the compressor and the vacuum pump, the endplateoverlaying and being adjacent to a stator of the compressor and a statorof the vacuum pump, wherein the endplate completely separates a firsthousing containing the first stator and a second housing containing thesecond stator, wherein the stator of the compressor, the stator of thevacuum pump, and the endplate all have the same height measured along adimension perpendicular to a long axis of the shaft, and wherein theendplate includes a only a single vent hole that extends through theendplate and communicates with ambient pressure, the vent hole beingpositioned entirely within the endplate and having (1) a first end thatcommunicates solely with an endplate chamber entirely defined by theendplate and entirely contained within the endplate (2) a second endthat communicates with the ambient pressure, wherein the vent hole isstraight along its entire length and extends radially outward from theendplate chamber to a radial end of the endplate and provides a solepassageway for fluid to vent out of the endplate chamber through theendplate and to atmosphere, and wherein the endplate chamber fluidlycommunicates with both the compressor and the vacuum such that gas canleak from the compressor or the vacuum into the endplate chamber,wherein the vent hole vents the gas that leaks into the endplate chamberto atmosphere; at least one sensor to detect patient breathing; and acontroller configured to control the oxygen delivery module to cause theoxygen delivery module to deliver the concentrated oxygen to the patientbased on data from the at least one sensor such that in response to adetermination, based on data from the at least one sensor, that nobreathing is detected for a first pre-determined period of time, thecontroller causes the oxygen delivery module to deliver the concentratedoxygen to the patient in continuous flow mode, and in response to adetermination, based on additional data from the at least one sensor,that breathing is detected for a second period of time, the controllercauses the oxygen delivery module to deliver the concentrated oxygen tothe patient in a pulse flow mode.
 2. The oxygen delivery device of claim1, wherein the at least one sensor is configured to detect patientbreathing by performing one of: continuous detection of patientbreathing, and periodic detection of patient breathing, wherein thecompressor and the vacuum are enclosed within a single housing.
 3. Theoxygen delivery device of claim 1, wherein the controller is furtherconfigured, subsequent to the determination that no breathing isdetected and to causing the oxygen delivery module to deliver theconcentrated oxygen to the patient in the continuous flow mode, to:terminate the continuous flow delivery of the concentrated oxygen to thepatient, and cause the oxygen delivery module to deliver theconcentrated oxygen to the patient in the pulse dose mode in response toone or more of: (a) a determination that the second period of time haselapsed since the determination that no breathing is detected, and (b)the determination, based on the additional data from the at least onesensor, that the patient is breathing.
 4. The oxygen delivery device ofclaim 1, wherein the at least one sensor includes a pressure sensorfluidly connected to a cannula coupled to the oxygen delivery module,the cannula structured to deliver the concentrated oxygen from theoxygen delivery module through the patient's nasal passages.
 5. Theoxygen delivery device of claim 4, wherein the pressure sensor fluidlyconnected to the cannula is configured to detect pressure changes withinthe patient's nasal passages, and to generate data representative of thepressure changes.
 6. The oxygen delivery device of claim 5, wherein thecontroller is further configured to: receive a feed of the datagenerated by the pressure sensor; perform filtering operation on thefeed of the data generated by the pressure sensor to determine onset ofan inspiratory cycle for the patient.
 7. The oxygen delivery device ofclaim 1, wherein the oxygen delivery module comprises one or more of: apressure swing adsorption system, a vacuum-pressure swing adsorptionsystem, a vacuum swing adsorption system, and a membrane separationdevice.